[TIMOB-9170] Support for building v8 for Android x86. Updated v8 to latest 3.9.
[TIMOB-9170] Enable x86 snapshot and improve error handling
[TIMOB-9170] Add -p to USAGE
Merge pull request #4 from appcelerator/timob-9170

[TIMOB-9170] Support for building v8 for Android x86. Updated v8 to latest 3.9.
Fix toolchain prefix for x86 builds.