highgui: Support to change trackbar count in setTrackbarPos and replaced deprecated CreateToolbarEx in Windows.

Fix tautologies in calibfilter.cpp which cause a build failure when using -Werror=address with clang-3.5

http://code.opencv.org/issues/4048Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>

There is necessary to account also x-ccordinate of the end of the edge when determining bounding box of the edge collection.

Move some static functions into the FarnebackOpticalFlow class as well,
so they can access these new class variables.

oclMat objects cannot be declared statically, because their destructor
depends on the statically defined __module variable from cl_context.cpp.
Since statically defined variables in separate compilation units have
an undefined destruction order there is always the possibility the
__module will be destructed before an oclMat object, which results
in a segfault.

It's needed for std::max.

gauss_w_lut is a statically defined variable of type oclMat.  The oclMat
destructor calls openCLFree() which via getInitializationMutex() accesses
the __module variable which has been statically defined in cl_context.cpp

Since the destruction order of statically defined variables in different
compilation units is undefined, it is possible that __module will
be destructed before gauss_w_lut, which would result in a segfault when
getInitializationMutex() is called while destructing gauss_w_lut.

In order to avoid this issue, we need to make gauss_w_lut a private
member of the HOGDescriptors class so we know it will be destroyed
before __module.