Auto-complete's `partial-complete` Should Escape Regex Special Characters

[ethagnawl]

It'd be nice (and instructive!) to have partial-complete escape regex special characters (e.g. [-[]{}()*+?.,^$|#\s]) in order to prevent the various errors which are currently thrown when entering special characters into the input filed. Done correctly, I believe this would also allow for autocompletion using said characters. (i.e. entering "?" would find "? and the Mysterians").

I'll work on submitting a PR but wanted to get the conversation started.