Based on the package/apps/Terminal implementation. I'll switch them over
shortly. This also lets us build the toybox version of netcat.
Change-Id: Ia922a100141a67409264b43b937eeca07b21f344
Also clean up the implementation of all the pty functions, add tests,
and fix the stub implementations of ttyname(3) and ttyname_r(3).
Bug: https://code.google.com/p/android/issues/detail?id=58888
Change-Id: I0fb36438cd1abf8d4e87c29415f03db9ba13c3c2
