Add Android support

Currently requires a loader that sets (int (*zdl_main)(int, char**)) to
the appropriate main function. 'main' actually works fine, as native
entries in Android are all through shared libraries.

Input needs some tweaking, but most of the plumbing is in place.

Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Acked-by: Kim Ahlstrom <kim.ahlstrom@sonymobile.com>
Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>