[boost] [boost-build] Android support

Greetings, There is a project at github, that has a series of patches for Android support. It contains android.jam and android.py files for bjam, and those files have Boost license https://github.com/MysticTreeGames/Boost-for-Android. Why don't we adopt those patches to boost trunk? This will help a lot of people, who use boost under Android. -- Best regards, Antony Polukhin