Split themes off into individual .css files

config.example.js now lists which themes are available for use by the client.

TODO: Auto-generate 'thumbnails' for the themes in the settings applet.
Auto-generate 'thumbnail' previews of themes in settings applet
Misc fixes

Correctly define link and remove superflous `var set_theme`
Move themes from client/assets/src/themes to client/assets/themes
Load themes as soon as possible to avoid FoUC

Also move theme configuration slightly to avoid sever-side caching bug
Added config option to disregard joins/parts from unread message counter.
Added hide-join/parts-from-configs to settings screen with en-gb translation only.
jump server reconnecting to the updated server addresses fix
Spaces could be encoded as '+' instead '%20'
Second IRC connection via /server fix
Leave transport management to engine.io
Channel Info+admin window; RPL_CHANNEL_URL; Ban list; CSS forms refactor
Merge branch 'development' of https://github.com/tonylechner/KiwiIRC into tonylechner-development
Config count_joins_parts > count_all_activity; Do not show joins/parts by default
Menubox - allow title change after rendered
channel info window tidying
Default gecos supporting user hostname insertion
Fix previous commit
Setting kiwi_server config via application options
gateway kiwi_server setting now only set in one place