Autocomplete with document content support

[gamecreature]

This seems pretty trival. But after giving some thought to it. This is pretty complex

• a wordlist of all words in the document needs to be build (This is do-able)
• this wordlist needs to be updated according to changes in the document. (removing and adding words)
• this needs to happen with a responsive document
• fuzzy searching the wordlist would be nice

For small textbuffers, regullary full-parsing is an option. For large documents this isn't an option and list updating needs to be smart.

I guess implementation version 1 will be full document parsing