Extra spaces in comments because of using TAB #162

This is a side effect of #117 I believe (pretty close to positive).

To use the available autocomplete when inserting a @ mention or emoji, you type <kbd>@</kbd>, <kbd>TAB</kbd> or <kbd>:</kbd>, <kbd>TAB</kbd>. This winds up adding extra spaces to the end of the comment. You don't really notice until you try to quickly get to the end of the text/line with <kbd>⌘</kbd><kbd>→</kbd>.

I have a sneaking suspicion that other keyboard events are adding spacing too, but I can't replicate it.