docs: Replace <structname> tags with back ticks

https://bugzilla.gnome.org/show_bug.cgi?id=731050
docs: Replace <function> XML tag with back ticks

https://bugzilla.gnome.org/show_bug.cgi?id=731050
MSVC 2010+ Projects: Update "Installation" Process

Currently, due to the way that Visual Studio 2010+ projects are handled,
the "install" project does not re-build upon changes to the sources, as it
does not believe that its dependencies have changed, although the changed
sources are automatically recompiled.  This means that if a part or more
of the solution does not build, or if the sources need some other fixes
or enhancements, the up-to-date build is not copied automatically, which
can be misleading.

Improve on the situation by forcing the "install" project to trigger its
rebuild, so that the updated binaries can be copied.  This does trigger an
MSBuild warning, but having that warning is way better than not having an
up-to-date build, especially during testing and development.
GActionEntry: improve documentation

Document that giving %NULL for the activate handler is supported since
GLib 2.40.  We documented this on GSimpleAction itself (where the
default handler functionality is implemented) but expecting the user to
dig that up is asking a bit much.

Also, add some more explicit documentation about the conditions under
which each field is expected to be filled in.

https://bugzilla.gnome.org/show_bug.cgi?id=732429
gspawn-win32: do not rely on __argc and __argv global vars.

Since we are getting passed Unicode values these global vars
might not have the correct value. Instead always get the wide arguments
and convert them to utf8 to use them.

https://bugzilla.gnome.org/show_bug.cgi?id=733146