select first item in list

Was broken for the new rawListItem stuff
fix getQuery regex to exclude trailing space, revert spaceTimeout

Was pulling in last word preceding a space at cursor pos,
i.e. "Mike " would return Mike after a space.

Reverting the spaceTimeout stuff, since we're going to limit
non-trigger queries to most recent word.
add onTriggerChar callback option

Will be called if the query is too short but begins with
triggerChar.  Passes the current string and a callback
that expects responseData in the same format as onDataRequest.
The intended use is to display an initial list of entities
for suggestion and to filter on that list even if it's
too short to trigger onDataRequest.