Android hints: Set osvers to getprop ro.build.version.release
Android hints: Add m to libswanted
Android hints: When Configure finishes, turn $^O into 'android'

During Configure, we want it to be linux-android, so that
it'll also go through all of the linux checks.
Configure, Android hints: Changes to allow native builds
Android hints: In native builds, add -L/system/lib to ldflags

This is just a safety net against the linker being weird.
Android hints: Clean up some files if cross-compiling with adb
Android hints: load the linux hints to get those defaults
pod/perlport.pod: Note which functions are not available on Android
Adjust fs test to try more ways of getting the CWD. Expire if we still didn't get it.
t/op/sprintf.t: Add Android to the list of skips for %.0g
t/op/sigdispatch.t: TODO tests that don't work on some Android builds
t/op/incfilter.t: Work around android only having an inbuilt echo
t/op/magic.t: Work around android only having an inbuilt pwd
t/op/magic.t: Skip tests that use env on Android
t/op/fork.t: Work around android only having an inbuilt echo
t/op/fork.t: Up the sleep time in a test to avoid timing issues
t/op/stat.t: use 'ls -l' on android, even if d_readlink is defined
t/op/sigdispatch.t: Increase timeout to avoid issues on slow processors
t/op/sigdispatch.t: SKIP, not TODO
t/porting/: Skips for cross-compilation