build: Fix missing backslashes in lists

https://bugzilla.gnome.org/show_bug.cgi?id=725496
girwriter: Don't add target for delegates without target

Fixes bug 725073.
girwriter: Set scope=call for delegates when async or notified does not apply

Fixes bug 725012.
girparser: Add array_null_terminated, fixes hand-written change in gio
posix: Declare Group.gr_mem as null-terminated

Fixes bug 725149.
glib-2.0: Add missing C header for symlink

Fixes bug 725151.
gtk+-3.0: Correct binding for IconView.convert_widget_to_bin_window_coords

The last two arguments are 'out'.
dbusserver: Rename the generated "parameters" identifier

Fixes bug 725555.
gio-2.0: Make Action.state, state_type and parameter_type nullable

Fixes bug 725367
gio-2.0: Also make Action.get_state_hint nullable
cogl-1.0: Fix some array arguments in Cogl.Texture
gio-2.0: Update to 2.39.91+

Fixes bug 726057
codewriter: Emit 'unowned' keyword for local variables

Fixes bug 726312
gtk+-2.0, gtk+-3.0: Make ComboBox.set_active_iter parameter nullable

Fixes bug 726141
libpq: Add PQping enum and functions

Fixes bug 722878
Accept single ellipsis parameter for instance methods

Fixes bug 726347
Add test for bug 726347
gstreamer-1.0: Make Element.add_pad parameter unowned

Fixes bug 702960
gstreamer-1.0: Make Bin.add_many first parameter unowned

Fixes bug 702969
gstreamer-1.0: Make Bin.add first parameter unowned