Changed __getitem__ to return raw items, rather than encoding them.
Large amounts of reworking:
	Changed most uses of encode/decode, instead of doing it several times,
decode once and encode when we save.

	Changed many strings to unicode to account for above change

	Load all now appends (NUM) to save file if the default one already
exists

In parse_file:
	regex for sentences now includes question marks and exclaimation marks
	
	Thanks to the switch to solely unicode, the sentence_col and file_col
pointers now work (before they were tracking raw character numbers,
rather than the converted unicode character number)

	Some logic in main repl loop reworkwed