Add IPP support in cvtColor function
Fix building the iOS framework after I dropped the VERSION macro.

This version uses CMake to generate Info.plist, which should be more
reliable than the old approach.
Fix a bug of retinaParameters.
When colorMode is set to 0 via Retina::_init method, _retinaParameters's
colorMode variable is not correctly assigned.
macros -> template in IPP support cvtColor
Merge pull request #4 from Itseez/2.4

OpenCV changes
Fix bilateralFilter function
Allow to read PNG image of color_type PNG_COLOR_TYPE_PALETTE with alpha channel
Correct reading PNG color type palette with or without alpha imread flags -1 or 1
Better not using pnginfo.h, using png_get_tRNS instead
using unsigned char instead of uint8_t to compile under windows
added a test for ocl::norm
fixer error with incorrect condition
Fix a potential bug of ParallelLoopBodyWrapper::operator(Range)
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.
removed NPP implementation
bugfix-for-3231
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."
Update build_framework.py
fixed problems with building iOS version
reorganize code for further modifiction
added custom implementation for nearest and linear interpolation
improved texture usage:

* use explicit extrapolation only for sub-matrixes
* use built-in interpolation for INTER_NEAREST mode
Merge pull request #1332 from pengx17:2.4_fix_parallel