Added test checking that all valid fourcc values are converted properly

Сonflict exists between some versions of libtiff and opencv headers

This should be safe todo unless we are writing a signal handler.

xioctl() assumes that ioctl takes int request. Cope with
  int ioctl(int d, unsigned long request, ...)
to avoid "invalid argument".

* Decouple Video4Linux2 support from Video4Linux as existence of
  v4l2 on a system does not imply support for v4l.
* Don't use V4L's struct video_window in V4L2 code.
* Removed __USE_GNU as comment says:
      /* support for MJPEG is only available with libjpeg and gcc,
         because it's use libjepg and fmemopen()
  so replace with test for fmemopen() if found necessary.

The video(4) driver provides a Video4Linux2 compatible API for
various video peripherals. This patch propagates HAVE_VIDEOIO if
the sys/videoio.h include file is found, which is the signature of
video(4).

OpenCV issue #2604

After this patch applied an attempt to encode empty images produces exception
saying "Raw image encoder error: Empty JPEG image (DNL not supported)"

when compiled with GStreamer, open (of a file) segfaults.

Fix was suggested by Bostjan Vesnicer.

Also fixed a typo in performance testing framework and removed hardcoded
temporary file name from highgui perf test

The change is based on pull request #211.

These codes should be included into regular builds.

disabled several tests on Mac when no FFMPEG is used; disabled automatic table initialization in imgwarp in the case of MinGW