Merge pull request #276 from hintjens/master

Problem: zproject was generating zyre_prelude.h
Problem: No builtin way to build for qt-android
Solution: Add qt-android build system and add to travis-ci
Merge pull request #277 from jemc/master

Problem: No builtin way to build for qt-android
Problem: Having a source file named zyre.c and it's header zyre_api.h is
inconsistent.
Solution:
   * move zyre.h to zyre_include.h
   * move zyre_api.h to zyre.h
   * include zyre_library in zyre.h
Merge pull request #278 from sappo/master

Problem: Having a source file named zyre.c and it's header zyre_api.h is
Problem: Generated build systems out of date
Solution: Regenerate from latest zproject
Merge pull request #279 from jemc/master

Problem: Generated build systems out of date
Switch to using zproject.gsl