basic vocab stuff - includes changes to wikiparser

Hi Jeremy,
as you are going to be working on the wikiparser, I have re-created and simplified my work on vocabs, issue #345 (as I think it is relevant) - this work includes changes to the tiddlywiki5parser - i.e.creating it from an abstract wikiparser. This abstract parser is also used to create parsers to support vocabs.
all the best
BJ