Revert "first test qt gui, working but not threadsafe, qthread is weird"

This reverts commit 4b161c6bbe3f5e0db7efe9f0176a7db33c4c4d19.

Conflicts:
	examples/simulators/simulator_fmcw.grc
	examples/simulators/simulator_fsk.grc
	examples/simulators/top_block.py
	examples/tests/qtgui_range_velocity.grc
	examples/tests/top_block.py
	lib/qtqui_range_velocity_impl.cc
	lib/qtqui_range_velocity_impl.h
revert to qt