Merge branch 'cleanup' into 'master'

CMakeLists.txt

include/libhqr.h

include/libhqr_common.h

include/libhqr_draw.h

include/libhqr_queue.h

src/queue.c

src/treedraw.c

src/treewalk.c

testings/CMakeLists.txt

testings/common.c

testings/common.h

testings/draw_hqr.c

testings/draw_systolic.c

testings/testing_hqr.c

testings/testing_pivgen.c

testings/testing_systolic.c

testings/testing_tileinit.c