[misc] Remove the hack of mc_instance.

Although it works, it also makes a hell in debugger.
[HTML] Fix error handling in html_init_module().

On some error paths, a OLE32.DLL or EOLAUT32.DLL could be errorneously
loaded even if not used (and never unloaded).
[VS2010] Add IMGVIEW files into MSVC project.
[examples/ex_html] Remove doublequotes from resource names.

MSVC resource compiler treats them as an ordinary char and it becomes part
of the resource name.
[VS2010] Add project for example ex_imgview.
[VS2010] Let MSVC to build all projects as C++.

According to Microsoft, "Build as C" is only for compatibility with old
sources incompatible with C++ and maintaining the (pure) C compiler is not
too high priority for them.