Editing capabilities after import

[sortedcord]

Adds ability to edit vocal elements after importing them from a text file. This allows for the following

• Deleting elements
• Editing element text
• Splitting elements
• Changing order of elements
• Line reset if manually edited

Closes #9

[sortedcord]

@gigareggie Made a few changes to how lyrics are handled I'm afraid the code is getting a bit too convoluted.. Need some feedback on that

[gigareggie]

I think it would be better to remove the line_index and word_index property from the VocalElements altogether and setup methods directly inside Lyrics to get adjacent elements. Also store elements directly inside lyrics using a matrix. The Line objects will not store the elements, instead would only contain other metadata and properties. This would probably cut down on the "rebuilding" that you are doing for now. That being said, I think it would be better to incorporate changes from the other branches before making breaking changes.

[sortedcord]

Well actually, word_index doesn't really contain the index of the element. I had been using it for splitting and joining syllables of a word.

[gigareggie]

Why not just use a flag like part_of_word for that? If an element has been tagged with that then it and the next element would be part of a single word. Is probably more simple than what's done here

pyAMLL/pyamll/parser/__init__.py

Lines 50 to 55 in f1d967b

	index = 0
	for i in range(len(self.elements)):
	if self.elements[i].word_index > index:
	_str += " "
	index = self.elements[i].word_index
	_str += str(self.elements[i])