Dim repeated time prefixes instead of hiding them

Makes the whole thing more square, is not too disturbing and makes it
possible to copy a single line with repeated time to include time in
clipboard.
glowingbear.css: fix indentation, remove unused colors
Emphasize self nick
Implement IRC nick completion uility
Swallow space after caret if needed (middle completion)
Switch between buffers with left Alt key only

Right Alt key, which is the same as Ctrl+left Alt, is used in several
keymaps to input special characters, like right Alt+2 in Canadian
French to input '@'. Do not switch between buffers when using right
Alt.

Fixes #67
Prevent default action for Ctrl+G

Ctrl+G is used in Chrome/Chromium, at least, to find the next match
(just like F3).
Nick completion support for end user

Closes #24
Support custom suffix for nick completion
Restore monospace/bright style for text inputs
glowing-bear.css: fix indentation
Do not handle keypress when not connected
Support case insensitive nick completion
Display host:port in top right corner when connected

Closes #69
Support colors in nick list
Add Escape and Alt+L keyboard shortcuts

  * Escape: disconnect
  * Alt+L: focus on input bar
No need to sort the flat nick list for completion

... because the completion function sorts it another way anyway.
Maintained cached flatnicklist, maintain shownicklist cached value for
template