Add method in StatModel class, to load from String

Added a method "loadFromString" which is based on the "load" one. It
allow to directly pass the XML string which can be usefull and faster
when you have a huge file in a variable.
Changing tabs to spaces.

Edited previous code to change tabs into spaces.
Re-editing Documentation

Attempting to re-editing the documentation, to satisfy buildbot error
status.
Re-edition of documentation

Re-edited the documentation again.
Build separate world-like iOS framework for contrib
highgui: Support to change trackbar count in setTrackbarPos and replaced deprecated CreateToolbarEx in Windows.
Fix SymmColumnSmallVec_32s16s SSE code
Specifically, in general antisymmetric case src[-1] (S0) should be
subtracted from from src[1] (S2), and not the opposite.
Removed "FORMAT_XML" to generalize format

Removed the "FileStorage::FORMAT_XML" to generalize format of the String
model.
add option to link to dynamic IPP libraries
Added better OpenNI2 support to the Asus Xtion and Occipital Structure
sensors which do not have image generators.
fix documentation bug 2432
Merge pull request #3448 from Ashod:highgui_trackbar_improvements
Merge pull request #3473 from TobyWanKenobi:master
Merge pull request #3491 from mshabunin:ios-extra-world
Changed CV_DbgAssert to CV_Assert when setting video modes for OpenNI2. Otherwise, in release mode the default modes never get set
Remove unnecessary local variable "size".

It should also be better for optimizing when compiling kernel.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
Use preprocessor for constant values in OpenCL kernel instead of
the parameter variable.

It could improve the performance of
OCL_Cascade_Image_MinSize_CascadeClassifier.CascadeClassifier/*.
Especially,
OCL_Cascade_Image_MinSize_CascadeClassifier.CascadeClassifier/15
OCL_Cascade_Image_MinSize_CascadeClassifier.CascadeClassifier/16
could be improved about 2% in Intel platform.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
fix obvious copy+paste typo in computeDistance()

(with this else-branch, argument contour2 would not be used at all)
Allow BGR, RGB, or gray capture via libv4l
For Java compatibility, avoiding explicit pseudonym in enum