Remove ATL Server headers.
Remove unused CLineNumberEdit.
Mpeg2SectionData: Add missing content type.
Remove always true checks.
GaussianKernel: Remove the assignment operator.
CompositionObject: Implement copy constructor.

Current design is error-prone. We don't even copy m_colors array. And if
one use default copy ctor m_pRLEData was also not copied.
CMouse: Remove the assignment operator.
Don't shadow class member.
MainFrm: Prevent window from moving when scale factor is too low to fit video.