Fix race condition in FloodPreventer

Need to lock data structures in the Flood Preventer as it could be
called from multiple threads.
Change tab stops

Change tab stops.
Fix empty chat line

Fix issue where the chat line is empty when icons haven't been loaded.
Better emoticon loading

Use existing emoticons instead of waiting for the threadpool to operate.
Add alternating color

Add alternating color to chat lines.
Add context menu items

Add profile/unban context menu items.
Hide scrollbar when not needed

Hide the scrollbar when it's not needed.
Fix off center notifications

Fix notifications being off center.
Chat input improvement

Increase size of input window and add a scrollbar.