FIX: Must repeat array elements, not the string representation of the indent number.
BUG: Off-by-one cursor position in single-line snippets without tabstops.
Set undo point before trigger expansion for easier undo.

For the new trigger implementation, set an undo point before attempting a trigger expansion (so that it's easier to undo only the snippet). Another (unavoidable) undo point is created after the initial expansion. The old trigger implementation somehow sets undo points after every inserted ^], anyway.