gstreamer: update built file
pango windows: fix a typo
glib2: fix indent
glib2 windows: add vendor path for not built module

For example, GI based bindings such as gdk3 doesn't need to build.
glib2 windows: clear needless prerequisites automatically

GI based bindings such as gdk3 doesn't need to build. So extconf.rb
doesn't exist.
gtk3: cairo-gobject's module name is cairo_gobject
gtk3: fix variable shadowing
gtk3 windows: add missing gdk3 dependency
Bundle cairo-gobject to ruby-gtk3 package

Because gtk3 requires cairo-gobject.