Fix snippets not working unless completion is hard invoked
They should not be completely disabled unless someone hard presses ctrl-space as it makes the experience very annoying. Overtime one can get used to the annoyance but I am not sure its a good idea.
The new logic honors ktexteditor minimal word length and starts the
completion if the last char is a letter. This should avoid the issue
with snippet completion starting on pressing .. However, this might
still be too simplistic but we can refine on it instead of hard
disabling the feature