stlport: deal with compile warnings

- In preparation for dependent projects to turn on
  -Werror and -Wunused

Change-Id: Ibf1b146d8d389e8747ba1ea1735cb55722b85971

Conflicts:
	stlport/stl/_stdexcept_base.c
stlport: c_locale_dummy unused argument warnings

Change-Id: Ib5e6736f83791c9795f9d4a5b5b8b201ed6327f6
Remove obsolete sincos from stlport

Change-Id: I12644a0e81d6dcf11d12530234678d178dbc4caf
Use the build system's STL selection.

This file is only kept around for compatibility so the change won't have
to go in as one mega-CL.

Change-Id: If712ba0ae7908d8147a69e29da5c453a183d6540