Revert "Revert "Bug 1053647: delete space when reverting an autocorrecti...

...on and don't insert space when user selects a word suggestion""

This reverts commit f643cb9858e6469f5736645943c0db508c829863. Testing this revert on suspicion that it is causing the Gip failures.

https://bugzilla.mozilla.org/show_bug.cgi?id=1053647