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
Removed redundant call to NAMES onJoin
Merge pull request #421 from CoryChaplin/development

Removed redundant call to NAMES onJoin
Update package.json to reflect new location of build.js
JOIN/PART/QUIT events being stored
SOCKS server fix
Net. interface binding per outgoing IRC connection
Updating DNSBL server module
Font formatting + colours in sent message (xchats %Cn format)
User menu location now depends on cursor location #420
Repeat incorrect password fix #243
Handle RPL_INVITING command
Client plugins loading correctly with new HTML templates
Make the window title configurable
Move window_title config option to client settings
Merge pull request #423 from M2Ys4U/title

Make the window title configurable