Android

Added a branch that add the cmake toolchain (http://code.google.com/p/android-cmake/source/browse/toolchain/android.toolchain.cmake) for android ndk build. For easy use I also added a shell script for linux which interacts with the user to build the library for android ndk, asking for ndk path, armeabi version and sdk version.

I also updated .gitignore for my working platform.