Merge branch 't/gui_improvements'

      gui: Make some functions return void.
      gui: Rename client_cmd_cmdline() to para_cmd().
      gui: Check return value of para_exec_cmdline_pid().
      gui: Also display command's stderr output.

diff --cc NEWS
index 7c3ac3ce2a9e727f24bf0f5e5829cb1762d7545c,5b87555053f907b1226fb1f2867f0d9076206ae9..dc83e1679a6981f7cda3b4cec605ddde5ff04dd8
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -2,9 -2,9 +2,14 @@@
  0.4.10 (to be announced) "heterogeneous vacuum"
  -----------------------------------------------
  
++Nothing earth-shaking in this release, but quite a few usability
++improvements and the usual mix of cleanups and fixes.
++
        - The --no_default_filters option of para_filter has been
--        depricated. It still works but has no effect and will be
++        deprecated. It still works but has no effect and will be
          removed in the next version.
++      - para_gui now prints also the stderr output of the executing
++         command in the bottom window.
        - Cleanup and consolidation of the various wrappers for
          write(), writev(), send() and friends.
        - The obscure error messages on mmap() failures have been
@@@ -13,9 -13,7 +18,8 @@@
        - para_audioc: Cleanups and memory leak fixes.
        - Test 0004-server no longer fails if para_server is not
          being built.
 +      - New configure options: --with-id3tag-{headers,libs}.
  
- 
  -------------------------------------
  0.4.9 (2011-12-06) "hybrid causality"
  -------------------------------------