removed from:
 - emoji panel scrollbars
 - emoji category labels
 - splitter image handles
 - textfield setTextColor impl

small change to the category separator label for better contrast /
readability in dark mode.

removed setTextColor completely from TextField. Doesn't appear to be in
use anywhere, and focus going more toward qss themeing from qproperty
setting.

The room list would be hidden only through window resizing.

Ctrl-O -> Chat
Ctrl-L -> Room list

fixes #160
fixes #163
fixes #187
fixes #127