Run AStyle on the source code.
Added 433, KICK and PRIVMSG event handling.

- 433 (nickname already taken) just appends an underscore to your
current nickname in an attempt to resolve the situation
- Client rejoins immediately after being KICKed (perhaps add a toggle in
settings and a configurable timer)
- Display nicely incoming PRVIMSGs while locally displaying outgoing
PRIVMSGs
Cleanup .pro file and don't use -std=c++11 on Windows platform.

The -std=c++11 parameter caused a warning when building with
QtCreator/VS2012 while not being required. Hopefully won't break MinGW
builds.