some more bits for windows compile
win32: Fix zlib build by respecting DESTDIR variable.
win32: Add --disable-cups to the Gtk configure call
win32: Adapt to the available libgcc dll

Automatically adapt the installer build to the available
libgcc shared DLL instead of hard-coding.
win32: Disable marshal rebuilds for GLib

Add --disable-rebuilds to the GLib configure args, to avoid
re-generating the gobject/gmarshal.[ch] files with an incorrect
glib-genmarshal from the build system. The system glib-genmarshal
is a later version for me, and generates an unbuildable gmarshal.c
that references g_value_get_schar.
win32: Update fontconfig cross-compilation patch

Make sure fontconfig doesn't use the Win32 link
flags as well as CFLAGS, as it breaks compilation
of the build-time tools.
win32: Make the installer build find translations correctly.

At some point my intltool.m4 started defining DATADIRNAME as 'share'
instead of 'lib', and putting the repsnapper translation files in
there, breaking the NSIS script. Substitute the correct value at
configure time so it works either way.
Merge upstream win32 fixes