fixed invalid output of cv::dft when using DFT_ROWS + DFT_COMPLEX_OUTPUT (http://code.opencv.org/issues/3428)

Replace asm by __asm__ according to
https://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate-Keywords
as suggested by Arnout Vandecappelle:
http://lists.busybox.net/pipermail/buildroot/2016-September/171491.html

to fix build errors in ffmpeg with opencv2 support detected by
buildroot autobuilders:
http://autobuild.buildroot.net/results/c32/c32a21240a9933796ee850349a62ff3c2314f25c/build-end.logSigned-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>

resolves #6944

Fix typo bug in the calculation of some derivatives (dmxdt, dmydt, dmxdr, dmydr) in cvProjectPoints2 function.

Add bib reference for overall hitrate and false alarm rate for the train cascade user guide (OpenCV 2.4).

to fix difference with CUDA 8.0 results