AI 146498: am: CL 145983 am: CL 145911 ADT #1778786: tool to generate stubbed jar file.

This is only a preliminary CL. More will follow but this is
  a good start, with the following caveats:
  What it does:
  - take an input jar, a list of includes, a list of excludes.
  - generate actual Java source for the filtered classes.
  What it doesn't do yet:
  - some more work on filtering inner elements (methods, etc.)
  - properly generate inner classes.
  - hide synthetic fields.
  - some classes body are missing
  - directly generate a stubbed bytecode/jar rather than source.
  I'll likely want to keep the source generator for debugging
  purposes or if we want to integrate with a build system instead.
  - classpath will be changed in the final CL to refer to the external
  ASM lib rather than the project. I need the source for debugging
  rigth now.
  - will review comments before submitting.
  Original author: raphael
  Merged from: //branches/cupcake/...
  Original author: android-build

Automated import of CL 146498

core/main.mk

@@ -345,6 +345,7 @@ subdirs += \
 	development/tools/ninepatch \
 	development/tools/sdkstats \
 	development/tools/sdkmanager \
+	development/tools/mkstubs \
 	frameworks/base \
 	frameworks/base/tools/layoutlib \
 	external/googleclient \