Merge branch 't/gui_sched'

Merge branch 't/gui_sched'

Was cooking for two months, since 2014-05-11.

* t/gui_sched: (53 commits)
  gui: Always initialize theme.
  gui: Simplify color handling.
  gui: Dont catch SIGWINCH.
  gui: Call waitpid() from exec and status task.
  Doxify para_gui.
  gui: Speed up window refresh.
  gui: Rename cmd_task to exec_task.
  gui: Move static variables of cmd_post_select() into struct cmd_task.
  gui: Move some variables into struct status_task.
  gui: Switch to the standard paraslash scheduler.
  gui: Use cpp magic to define command handlers.
  gui: Execute stat command in status_post_select().
  gui: Rename COMMAND/EXTERNAL/GETCH mode.
  gui: Get rid of do_select()'s mode parameter and call it only once.
  gui: Reorder functions.
  gui: Move signal handling code out of do_select().
  gui: Move input related code out of do_select().
  gui: Move external command handling out of do_select().
  gui: Introduce status_post_select().
  gui: Improve config reload.
  ...