Fixed MATLAB bridge

MATLAB bridge.hpp was missing definition for Ptr<DenseOpticalFlow>
Merge branch 'master' of https://github.com/Itseez/opencv
DownhillSolverImpl::innerDownhillSimplex something looks broken here:
Mat_<double> coord_sum(1,ndim,0.0),buf(1,ndim,0.0),y(1,ndim,0.0);
nfunk = 0;
for(i=0;i<ndim+1;++i)
{
y(i) = f->calc(p[i]);
}
y has only ndim elements, while the loop goes over ndim+1
Unroll pyrUp kernel
Added new border types for pyrDown
Optimize OpenCL LUT function
Use 4 pixels for one unit. Some ocl code refactoring
Optimize OpenCL LUT function
Optimize OpenCL LUT function
Fix some errors
Fix some errors
Removed useless multiplication by 4
Updating missed defines in documentation

Updating missed defines in documentation. The new defines (in imgproc.hpp) state they have a prefix of COLOR instead of CV.
optimized index calculation
optimized cv::countNonZero
optimized cv::sum (CV_8UC1)
optimized cv::UMat::dot
Fixed inconsistency with flag names

Fixed inconsistency with flag names for solvePnP. 
The default value for the function lacks the CV_ prefix. The code checks against "ITERATIVE". The suggested values for the parameters *include* the prefix.
Even though the enum CV_ITERATIVE (+ CV_P3P, CV_EPNP) = ITERATIVE (& P3P, EPNP), lets show to the users only one of them.
Now the user sees only {ITERATIVE, P3P, EPNP}.
perspectiveTransform simplify assert() for better debuggin

When using perspectiveTransform in rather complicated settings, it would be easier for developers to have two separate assertions for each part of the boolean expression in order to pinpoint problems more efficiently. In my case I am struggling in Python2.7 with finding out whether scn+1 == m.cols or the depth == CV_32F || depth == CV_64F is making a problem, which is kind of hard.
fix typo in linux tutorial