(2.4) Backports from master branch (#7854)

Pdb file support was changed in CMake 2.8.12, support was added in CMake 3.1.0 to work around the problems created by the change introduced in CMake 2.8.12.

(cherry picked from commit b75cbfde)

Conflicts:

	cmake/OpenCVModule.cmake

Allow to build samples via OpenCV binaries from distribution package
(find_package with OpenCV_DIR).

They're not listed in the documentation for the FindZLIB module,
so we shouldn't use them unless necessary.

exclude IlmImf/b44ExpLogTable.cpp from the build,

it's used originally to generate IlmImf/b44ExpLogTable.h, but not nessecary for the library.(probably only here for documentation

when included with static linking it introduces a problem with multiple definitions of main()