Fix live auto completion.
Didn't set completers when enabling it.
Update text_completer and util to support unicode characters autocomplete.
Update language_tools to support pass in completers at enableLiveAutocomplete and enableBasicAutocomplete so user can further customize the completion behavior.
Rename enableLiveAutocomplete to enableLiveAutocompletion to match enableBasicAutocompletion
Update regex and condition check according to suggestion
Merge pull request #1924 from unional/liveAutocomplete

Improve auto complete