** Don't try to set a global variable in the same file as a class definition (Profiler.php). Set it in WebStart.php instead.
** In StartProfiler.sample, don't use require_once() to get ProfilerStub.
* Removed the setproctitle() stuff from ProfilerStub, the extension is not maintained and doesn't work with Apache 2.x
* Added an optimisation to wfProfileIn() and wfProfileOut() to reduce the overhead when profiling is not enabled
* Added the ability to configure in StartProfiler.php whether CPU time or wall-clock time is used, avoiding recompilation
* Move autoloader up a little bit so the profiler classes can use it
* Make Profiler into a singleton so it's lazy-constructed, $wgProfiler is now a configuration array (used 'visible' in ProfilerSimpleText as an example of other globals we can move into this array). If $wgProfiler is set to an object, it'll use that for back-compat
* Maintenance: rather than setting up the profiler and then disabling it, just disable it from the start
* Kill $wgProfiling -> now that ProfilerStub overrides profileIn() and profileOut(), it's not needed
* dumpHTML needs some fixes still
