Allows .vue files to be used in package modules as if they were .js
files: they can be added to the 'packageFiles' array in module
definitions, and require()d from JS files.
In the load.php output, each .vue file is transformed to a function that
contains the JS from the <script> tag, then a line that sets
module.exports.template to the contents of the <template> tag (encoded
as a string). The contents of the <style> tag are added to the module's
styles.
Internally, the type of a .vue file is inferred as 'script-vue', and the
file is parsed with VueComponentParser, which extracts the three parts.
After the transformation, the file's type is set to 'script+style', and
files of this type contribute to both getScript() and getStyles().
This change also adds caching to getPackageFiles(), because it now needs
to be called twice (in getScript() and getStyles()).
Change-Id: Ic0a5c771901450a518eb7d24456053956507e1ed
ca46126e98
