Visual Studio Builds: Fix "Installation" Process

Install the Python scripts under collections/ and doctemplates/, especially
the scripts under collections are required during the run of g-ir-scanner.
tests: Fix make dist
Update annotations from glib git
gimarshallingtests: Add test for GValue pass-by-reference

https://bugzilla.gnome.org/show_bug.cgi?id=701058
Release 1.37.4
Update annotations from glib 2.37.4
Update annotations from glib git
Visual Studio builds: Update _giscanner Project

Add the "PC" folder in the Python installation root as one of the include
folders, as that is where pyconfig.h would reside (at least for the people
that compiled Python themselves from source using Visual Studio)
MSVC Builds: Fix "Installation" Process again

My previous commit on this (d2613dd9) didn't quite get it right then and
some items were missed from that commit.  Get that corrected, and ensure
also the scripts/templates in collections/ and doctemplates are "installed"
accordingly.
scanner: Consistently use realpath() on input filenames

The scanner has some logic to compare the filenames specified
on the command line against files it will parse.  For the latter,
it uses g_realpath().  With this patch, we also use g_realpath()
on the command line arguments.

This fixes g-i when used inside jhbuild in a gnome-ostree VM,
which has a symbolic link /home -> /sysroot/home.  This caused
a realpath mismatch, and then we'd ignore the input source files.

It'd be best to get out of the realpath business entirely...but
a patch to do that seems more likely to break.

https://bugzilla.gnome.org/show_bug.cgi?id=704864
Update annotations from glib 2.37.5