Replace stlport source with prebuilts.

This will prevent anyone that's unaware of its deprecation *and* the
correct way to use an STL from the build system from just adding the
includes and the shared library to their module manually.

Bug: http://b/21035951
Change-Id: Ibe03fb6cc9dea9c74853e30a6a1f1425035da22a
685 files changed