Remove the build_all option on Mac for now to prevent building
both debug and release libraries in the same run since it causes
linking issues with framework builds of Qt because of the
platform suffix of debug libraries.
Eventually the build system should be adapted to Mac specific
configurations.
Create unix binaries instead of app bundles to ease testing since
currently the examples need DYLD_LIBRARY_PATH to run.

Change-Id: I7fe3a7e6963510fb5a8863d9e68df487c168ff20
Reviewed-by: Zeno Albisser <zeno.albisser@digia.com>