Fix bug leading to crash when playing video and the backing model changed order of items
glw: Fix bug causing almost no UI output on RPi
blobcache: Fix use of uninitialized memory
Correctly reparent items in metadata cache
pool: Make it possible to do pool allocation using malloc() only

Makes stuff easier to troubleshoot when using valgrind
rstr: Make it possible to disable refcounting in rstr

Makes it easier to find leaks with valgrind
Fix various memory leaks
Fix a couple of build errors