autotools: Re-enable and enhance the completion of MSVC projects

autotools: Re-enable and enhance the completion of MSVC projects

-Isolate the creation of full MSVC projects for pango, pangoft2 and
 pangocairo in a seperate build/Makefile-msvcproj.am, so it can be included
 and used elsewhere.
-Update the Makefile.am's in pango/ and pango/mini-fribidi to include
 and use build/Makefile-msvcproj.am to create the MSVC project files
-Use templates for the property sheets so that the listings of header files
 to "install" can be filled in using build/Makefile-msvcproj.am, to
 simplify future maintenance.
-Re-enable the distribution of the created project files and property
 sheets