Fixed compilation errors under VS 2010 and Win 7

Applied in PR3240 to 2.4 branch.
Fix linking error under Win 7 - do not import MinCore_Downlevel.lib if target is Win 7 or earlier.

Applied in PR3243 to 2.4 branch.
Fixed MSMF video capture initialization

Applied in PR3251 to 2.4 branch.
Fixed assertion warning in MSMF frame grabber

Applied in PR3251 to 2.4 branch
Fixed MSMF file capture error while opening the file containing unsupported video stream format

Applied in PR3260 to 2.4 branch
CMake configuration for MSMF capture

Applied in PR3247 to 2.4 branch.
Merge pull request #3267 from a-wi:MSMF_capture_fixes_v3