Add Makefile.android to distribution/manifest
chicken.h: set software-type and software-version to android when __ANDROID__ is defined
changes on posixunix for the android toolchain

Signed-off-by: Mario Domenech Goulart <mario.goulart@gmail.com>
posixunix: user-information always yields "" for gecos on android

pw_gecos is not available on the passwd struct on android, so we just
set that information as "".