#221 and #222 have exposed some weaknesses in the design of the autocomplete functionality.

41d046e should mostly address the problems raised there, but in the long run, the autocomplete functionality should be refactored:

• Right now it's building matches that include the prefixes, and this llmits the flexibility of the searches
• Space handling is hard, and although kind of working now, looks ugly using the backslash character. Ideally, single quotes would be better.