Bug 900522 - Part 1: Make ANDROID_RESFILES a moz.build-only variable. r=gps

This depends on Bug 923306, which I think is close to r=glandium.
Since this is more moz.build than Android, r?=gps.
Bug 900522 - Part 2: Use ANDROID_RESFILES in mobile/android/base/moz.build. r=gps

This defines ANDROID_RESFILES in mobile/android/base/moz.build but
does not use the default processing from java-build.mk.
* * *
Bug 900522 - Part 1: Make ANDROID_RESFILES a moz.build-only variable. r=gps
Bug 900522 - Part 3: Add passthru ANDROID_GENERATED_RESFILES. r=gps

This defines all of the Android resources in moz.build files (although
some are still generated by mobile/android/base/Makefile.in).