Add nickchange plugin

This is related to candy-chat/candy#205
Fix roomPanel for non-ASCII room names
Fix ugly room toolbar icon
RoomPanel now with new room button in tab list

Fixes #59

Might need further testing
Fix README, screenshot & css
roomPanel: fix tab style. better defaults.
Added Join Plugin from amiadogroup
Embed Youtube videos automaticly
Merge pull request #61 from maennchen/feature/Inline_Videos

Embed Youtube videos automatically
README updated
Main Readme
verry simple plugin to join rooms
Updated Class and description
Merge pull request #63 from maennchen/dev

Updated Class and description
Merge pull request #62 from maennchen/feature/Available_Rooms

merge available-rooms plugin
Merge branch 'feature/Available_Rooms' into dev
Merge pull request #60 from maennchen/feature/Join_Command

Added Join Plugin
Merge branch 'feature/Join_Command' into dev
Merge branch 'dev' of github.com:candy-chat/candy-plugins into dev
Update/Fix README