Fix realpath issue.
Note that the realpath code implementation is copy in init.c and renamed to c_realpath.

See https://github.com/bigfatbrowncat/avian-pack.android.libcore/issues/1#issuecomment-45416940
realpath
strerror_r committed and implemented properly (PR submitted)
Taking notes on the code (PR to libcore64)
Merge branch 'link_windows_libcore64' of https://github.com/PerfectCarl/robovm into link_windows_libcore64