add structs.scad to std.scad; fix various it's typos in docs

.openscad_docsgen_rc

@@ -35,6 +35,7 @@ PrioritizeFiles:
   skin.scad
   vnf.scad
   beziers.scad
+  nurbs.scad
   rounding.scad
   turtle3d.scad
   math.scad

ball_bearings.scad

@@ -50,8 +50,8 @@ module ball_bearing(trade_size, id, od, width, shield=true, flange=false, fd, fw
         ball_bearing_info(trade_size);
     check = assert(all_defined(select(info, 0,4)), "Bad Input");
     if(flange){
-        assert(!is_undef(fd), "If flange is set you must specify it's diameter");
+        assert(!is_undef(fd), "If flange is set you must specify its diameter");
-        assert(!is_undef(fw), "If flange is set you must specify it's width");
+        assert(!is_undef(fw), "If flange is set you must specify its width");
     }
     id = info[0];
     od = info[1];

gears.scad

@@ -465,7 +465,7 @@ function _inherit_gear_thickness(thickness,dflt=10) =
 //   It is possible to design the worm to follow the curved shape of its mated gear, resulting
 //   in an enveloping (also called "globoid") worm.  This type of worm makes better contact with
 //   the worm gear, but is less often used due to manufacturing complexity and consequent expense.  
-// Figure(3D,Big,NoAxes,VPT=[0,0,0],VPR=[192,0,180],VPD=172.84): A cylindrical worm appears on the left in green.  Note it's straight sides.  The enveloping (globoid) worm gears appears on the right in green.  Note that its sides curve so several teeth can mate with the worm gear, and it requires a complex tooth form
+// Figure(3D,Big,NoAxes,VPT=[0,0,0],VPR=[192,0,180],VPD=172.84): A cylindrical worm appears on the left in green.  Note its straight sides.  The enveloping (globoid) worm gears appears on the right in green.  Note that its sides curve so several teeth can mate with the worm gear, and it requires a complex tooth form
 //   tilt=20;
 //   starts=1;
 //   ps=0;

rounding.scad

@@ -1249,7 +1249,7 @@ function _stroke_end(width,left, right, spec) =
 function _path_line_intersection(path, line, ind=0) =
         ind==len(path)-1 ? undef :
         let(intersect=line_intersection(line, select(path,ind,ind+1),LINE,SEGMENT))
-        // If it intersects the segment excluding it's final point, then we're done
+        // If it intersects the segment excluding its final point, then we're done
         // The final point is treated as part of the next segment
         is_def(intersect) && intersect != path[ind+1]?
                 [intersect, ind+1] :
@@ -2210,10 +2210,11 @@ module rounded_prism(bottom, top, joint_bot=0, joint_top=0, joint_sides=0, k_bot
   dummy1 = assert(in_list(atype, ["intersect","hull","surf_intersect","surf_hull","prismoid"]),
                   "Anchor type must be one of: \"hull\", \"intersect\", \"surf_hull\", \"surf_intersect\" or \"prismoid\"")
            assert(atype!="prismoid" || len(bottom)==4, "Anchor type \"prismoid\" requires that len(bottom)=4");
+  
   result = rounded_prism(bottom=bottom, top=top, joint_bot=joint_bot, joint_top=joint_top, joint_sides=joint_sides,
                          k_bot=k_bot, k_top=k_top, k_sides=k_sides, k=k, splinesteps=splinesteps, h=h, length=length, height=height, l=l,
                          debug=debug, _full_info=true);
-
+  height = one_defined([l,h,height,length], "l,h,height,length", dflt=u_add(bottom_height,top_height));
   top = is_undef(top) ? path3d(bottom,height/2) :
         len(top[0])==2 ? path3d(top,height/2) :
         top;
@@ -2792,7 +2793,7 @@ Access to the derivative smoothing parameter?
 //   prism axis with the auxiliary object.  Note that this means that if `aux_T` is a rotation it will change the joiner prism root, because
 //   the rotated prism axis will intersect the base in a different location.  If you do not give an auxiliary object then you must give
 //   the length/height parameter to specify the prism length.  This gives the length of the prism measured from the root to the end point.
-//   Note that the joint with a curved base may significantly extend the length of the joiner prism: it's total length will often be larger than
+//   Note that the joint with a curved base may significantly extend the length of the joiner prism: its total length will often be larger than
 //   the length you request.  
 //   .
 //   For the cylinder and spherical objects you may wish to joint a prism to the concave surface.  You can do this by setting a negative

std.scad

@@ -37,6 +37,7 @@ include <skin.scad>
 include <vnf.scad>
 include <utility.scad>
 include <partitions.scad>
+include <structs.scad>
 
 // vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap
 

structs.scad

@@ -5,9 +5,9 @@
 //   by key.
 // Includes:
 //   include <BOSL2/std.scad>
-//   include <BOSL2/structs.scad>
 // FileGroup: Data Management
 // FileSummary: Structure/Dictionary Manipulation
+// FileFootnotes: STD=Included in std.scad
 //////////////////////////////////////////////////////////////////////
 
 

turtle3d.scad

@@ -460,7 +460,7 @@ function _turtle3d_command_len(commands, index) =
     in_list(commands[index],["repeat","arctodir","arcrot"]) ? 3 :   // Repeat, arctodir and arcrot commands require 2 args
     // For these, the first arg is required, second arg is present if it is not a string or list
     in_list(commands[index], one_or_two_arg) && len(commands)>index+2 && !is_string(commands[index+2]) && !is_list(commands[index+2])  ? 3 :  
-    is_string(commands[index+1]) || is_list(commands[index])? 1 :  // If 2nd item is a string it's must be a new command; 
+    is_string(commands[index+1]) || is_list(commands[index])? 1 :  // If 2nd item is a string it must be a new command; 
                                                                    // If first item is a list it's a compound command
     2;                                 // Otherwise we have command and arg