This is fixed upstream in mariusmuja/flann@b615f26, but that fix
would break binary compatibility, so I had to make a different one.

Since the bug isn't quite obvious, here's an explanation. In the const
version of any::cast, if policy is a small_any_policy, its get_value
returns its input argument. So r becomes a pointer to obj, and the
return value is a reference to a local variable, which is invalidated
when the function exits.

facerecognizer interface + white + whitespaces remove

libpng 1.5+ recommends a call to png_set_interlace_handling() if you use
png_read_update_info and png_read_image. It will generate a warning
without it.

Also removed malformed tEXt chunk from a logo PNG.

enabled some tests that failed before OCL_TEST_CYCLE*() macroses were defined and for some tests was disabled SANITY_CHECK, because plain and ocl results must not be completely equal

fixed building OpenCV with IPP 6.x (different DFT API); added Canny and rectangular morphology (based on Alex Kapustin patches)

See pull request #1241 for why.

do not calculate sum of error in every round of iteration;
instead the error will be summed every 2nd times or more, 
if the previous sum of error is too far away from threshold.

* use explicit extrapolation only for sub-matrixes
* use built-in interpolation for INTER_NEAREST mode

Changed the brief description of function Mat::colRange from "Create a matrix header for the specified row span." to "Create a matrix header for the specified column span."

On a 32-bit compiler the calculation may result in data (size_t) overflow when running some paralleled algorithms (which can safely run on a 64-bit compiler).
This bug is found when running OpenCV's Retina tutorial on 32bit VS2010.