In some cases changing the type used was enough, in some others I just force
casted things as too many changes would be required and overflow unlikely
(for array marshalling the cache uses gssize while the marshalling code uses
garray and thus guint)

My hope is that having this enabled will improve things gradually with
future cleanups.

No need to have two similarly named files

There is no pyglib anymore

This reverts commit fa555767464fbe551b14cfbc121febc5290b1371.

This reverts commit 80eab029ce4e181624d7b845a4b517051797080d.

Similar to what is done for marshalling from python, we
collect cleanup data that will then be passed on to the
cleanup function.

the overflow happens on windows platforms when an unsigned
flags value overflows the capacity of a signed long
on windows long is a 32-bit signed integer.

fixes https://bugzilla.gnome.org/show_bug.cgi?id=786948

Move all the random declarations in pygobject-private.h to their
respective header files. Rename pygobject.c to pygobject-object.c
so it's clearer that it's not the implementation of pygobject.h.
Add a new pygobject-internal.h which includes pygobject.h
with _INSIDE_PYGOBJECT_ defined like pygobject-private.h did.

In case you are looking at the git log and end up here due to the
rename try:

  git log --follow pygobject-object.c

or on the web interface go to the history of the old file name:

https://git.gnome.org/browse/pygobject/log/gi/pygobject.c?id=6b702c052e9f26e809cff494f0c896d17a514c64

https://bugzilla.gnome.org/show_bug.cgi?id=767084