msvc: switch to dynamic library

made similar to glibmm, with the gendef program

        * .gitignore: added gendef's automatically generated project files
        * MSVC_2010/gendef/gendef.cc:
        * MSVC_2010/gendef/gendef.vcxproj:
        * MSVC_2010/gendef/gendef.vcxproj.filters: symbols generator added
          (just like in gtkmm project)
        * MSVC_2010/gstreamermm.sln: added gendef's project to a main
          solution
        * MSVC_2010/gstreamermm/gstreamermm.vcxproj: switched build to
          dynamic library, ran gendef program before build
msvc: don't generate debug info in release

        * MSVC_2010/gstreamermm/gstreamermm.vcxproj: disabled debug info
          generation in release configuration
msvc: enable rtti

        * MSVC_2010/gstreamermm/gstreamermm.vcxproj: rtti enabled
msvc: disable some optimizations

        * MSVC_2010/gstreamermm/gstreamermm.vcxproj: disabled
          optimizations according to glibmm msvc project