py: Add %q format support to mp_[v]printf, and use it.

py/argcheck.c

py/bc.c

py/builtinimport.c

py/emitinlinethumb.c

py/emitnative.c

py/mpprint.c

py/obj.c

py/objdict.c

py/objexcept.c

py/objfun.c

py/objgenerator.c

py/objmodule.c

py/objnamedtuple.c

py/objtype.c

py/runtime.c

tests/micropython/meminfo.py.exp