server: move memset after check

If the malloc fails, memset would touch invalid memory.

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
tests: add tests for bug in adding socket

Last set of commits introduced a bug. When adding of socket with
a particular name fails, then the socket and its lockfile are deleted
regardless who created the socket.

/* OK */
wl_display_add_socket(display, "wayland-0");

/* this call fails and will delete the original socket */
wl_display_add_socket(display, "wayland-0");

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
server: fix error handling when adding socket

When some function during adding socket fails, it must clean
everything it set or we can get funky errors.

This patch fixes:
http://lists.freedesktop.org/archives/wayland-devel/2014-August/016331.html

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
util: list corruption is bad
server: Don't expose wl_display as a global

The idea here was that once upon a time, clients could rebind wl_display
to a higher version, so we offered the ability to rebind it
here. However, this is particularly broken. The existing bind
implementation actually still hardcodes version numbers, and it leaks
previous resources, overwriting the existing one.

The newly bound resource *also* won't have any listeners attached by the
client, meaning that the error and delete_id events won't get delivered
correctly. Unless the client poked into libwayland internals, it also
can't possibly set up these handlers correctly either, so the client
will sustain errors and leak all deleted globals.

Since this never worked correctly in the first place, we can feel safe
removing it.
server: Move a typedef where it's used
server: Rename wl_global's data to bind_data

We're going to add a new field for the simpler interface soon.
server: Add a new, simpler API for creating and binding globals
server: Deprecate the old wl_global_create API