Clarify expectations with error codes like G_IO_ERROR_FAILED

If an error code enumeration is expected to be extended in the future,
people shouldn't compare explicitly against its generic "FAILED" value.

https://bugzilla.gnome.org/show_bug.cgi?id=726775
gio/tests/socket: skip IPv6 tests on IPv6-less machines

https://bugzilla.gnome.org/show_bug.cgi?id=667468
Updated Hungarian translation
Update Czech translation
socketclient: Fix leak

https://bugzilla.gnome.org/show_bug.cgi?id=726611
gio: fix two more g_task_return_error_if_cancelled() leaks

https://bugzilla.gnome.org/show_bug.cgi?id=726611
GSocket: ignore timed out state when not relevant

Do this by separating the timeout check from the other socket checks.

https://bugzilla.gnome.org/show_bug.cgi?id=726375