(cherry picked from commit 286ab97d)

Workaround if save to a cache folder fails, just drop the attachments, if any.
Respective console (book/cal/mail) contains critical warnings about this situation.

https://bugzilla.gnome.org/show_bug.cgi?id=654950

(cherry picked from commit 0b90dbc8)

This patch is a workaround that avoid the crash without mess with the
functions using the returned values. A proper fix can be done as soon
we figure out the real cause of the problem.

The minimum Evo/EDS version requirement was horribly out-of-date.

(cherry picked from commit 67c1e987)

Fix leak in cache_lock rec_mutex and in state_lock mutex

(cherry picked from commit 8cdffc04)