Android limited load file

This set of commits works around the "Load File" problem with Android builds by bypassing the standard Android file dialogs and just reading the list of files directly from a hardcoded location on the sdcard.  "Save to File" was similarly updated to save files to the same hardcoded directory using "playername.coc".

The build setup was slightly changed to add this direct file-handling functionality.  A separate .swf file is generated for browser/standalone builds vs AIR builds.  Since File access is needed for this direct file-handling functionality, it is only available in the AIR builds.  The browser/standalone builds will continue to use the system dialogs.