Fix incorrect implementation of static memory.

vmtranslator/operations/memory.py
	-The initial implementation of static memory (in the context of
	`push` and `pop` commands) was incorrect, simply treating it as
	any other static segment and not creating globally unique
	labels.
	-Modify `MemoryOp.__init__()` and `MemoryOp.from_string()` to
	accept and pass a `module` argument, which is used by the newly
	defined `MemoryOp._get_static_label()` to create unique labels
	for operations on the `static` memory segment.

vmtranslator/translator.py
	-Keep track of the current file ("module") in the `state`
	dictionary.