Things To Do
                            (in no particular order)


* Allow clamping to a GL version or a number of extensions.

* Match the traced visuals

* Trace multiple threads
  * GetCurrentThreadId()
  * pthread_self()

* Put zlib (de)compression in a separate thread.

* Trace TSCs

* Retrace multiple threads

* Provide a readline-like interactive mode to gltrace
  * http://github.com/antirez/linenoise
    * https://github.com/antirez/linenoise/issues#issue/8
  * http://hg.youterm.com/radare/file/87579f8c5087/src/dietline.c 

* Trace window sizes somehow

* Plug memory leaks.

* Allow to distinguish between the calls really done by the program, vs the
  fakes one necessary to retrace correctly.