Fix default textureSize config option.
Add IPC:

  Manaplus now accepts connections on the 44007 port.

  * Uses SDL_Net/SDL_Thread.
  * Port can be changed with envvar IPC_PORT.
  * Default port is first checked then incremented until one is available.
  * start on demand with /ipctoggle (shuts down server socket)

  It has a simple text protocol: TYPE arg1 [args]...
  Message types:
   * CMD: execs a command supported by manaplus, e.g /emote
   * LTALK: talks in general tab
   * TALK: talks in current focused tab
   * [TODO] KEY: do as if the KEY was pressed on keyboard
IPC: fix copyright
IPC: remove message typesr; forward raw string to chatInput
fix warnings from mplint
Fix different style issues in ipc code.
Remove from ipc code try/catch and add missing check.
Fix possible infinite loop in ipc code.
Fix memory leak with ipc port selection.
Add some new functions into sdltcpnet.
In ipc code replace SLD_net into tcpnet.
Fix memory leak in ipc on client exit.
In ipc add copy protection.
Reorder variables in ipc.
Remove unused include from ipc.
Add missing files into cmake.
In ipc replace some other SDL_net calls into TcpNet.
update translations.
Yellow bar action methods add support for back and forward switch.

For now unused.
Simplify yellow bars action.