Windows: added project files for Visual Studio 2010

	* MSVC_2010/gstreamermm-1.0.props: property sheet (it should help
	  gstreamermm's users create own project, which uses gstreamermm.
	  File contains include directories, library paths needed for
	  compilation apps based on gstreamermm.
	* MSVC_2010/gstreamermm.sln: solution file
	* MSVC_2010/gstreamermm/gstreamermm.rc: resources file
	* MSVC_2010/gstreamermm/gstreamermm.vcxproj: gstreamermm visual
	  studio's project file (also uses gstreamermm-1.0.props).
	* MSVC_2010/gstreamermm/gstreamermm.vcxproj.filters: vs filters
	  file.
	* MSVC_2010/gstreamermm/gstreamermmconfig.h: file contains
	  gstreamermm configuration.