Selection clears redo

[1j01]

Also it doesn't restore selections when undoing/redoing, it just selects everything.

[1j01]

After implementing undo/redo button graying (when there are no undos/redos), it's clear it's actually the unfocusing logic (which parses and stringifies tablature)

guitar/src/app.coffee

Lines 220 to 226 in 21b3b3c

	# @TODO: maybe listen for change and indicate that you need to unfocus it to update
	# or better yet just conditionally show a button
	tablature_editor.editor.on "blur", ->
	text = tablature_editor.editor.getValue()
	load_tablature(text)
	return