[Android] first implementation:
1. created DirectBuffer implementation.
2. added test for memory mapped file.
3. enhanced the build process to build the android jars too.
4. added dexmaker which is needed in order to be able to use mockito on android (dexmaker provides a plugin for mockito)
5. added targets to build file to create and run a testpackage on a device.
    All tests except the code generator ones, successfully run on Android.
[Android] did a little cleanup and fixed permissions for tests
[Android] fixed retrieval of test results from device
[Android] fixed some warnings
[Android] DirectBuffer compatible with Android 4.0 (API 14) or later
[Android] DirectBuffer performance improvements
[Android] DirectBuffer more performance improvements
[Android] DirectBuffer cleanup and code tidy
[Android] 1. DirectBuffer rolled back some changes
                 2. Added javadoc target for android
[Android] fixed apk signing for tests
[Android] build libcore.io.memory.jar using java 6 as source and target
Merge branch 'master' into android-preview
[Android] Updated README.md
Merge branch 'master' into android-preview
Merge pull request #196 from csoroiu/android-preview

Android support #171