After a while, evolution stops using spamassassin for junk mail detection.

Here is what happens:

1- Evolution creates spamd socket and pid file in ~/.cache/evolution/tmp with e_mktemp()
2- When creating a new temporary directory to open an email attachment, evolution notices that the socket and pid file are more than 2 hours old, and deletes them, breaking spamassassin integration

See TEMP_EXPIRE in e-util/e-mktemp.c.

The problem is that it's using st.st_atime, but that's no longer getting updated on Ubuntu and/or with ext4.

This is my directory before opening an attachment:
mdeslaur@mdlinux:~/.cache/evolution/tmp$ ls -al
total 24
drwxr-xr-x 5 mdeslaur mdeslaur 4096 Jun 18 12:49 .
drwx------ 6 mdeslaur mdeslaur 4096 Apr 10 2011 ..
drwx------ 2 mdeslaur mdeslaur 4096 Jun 18 12:49 evolution-mdeslaur-PlMVtk
drwx------ 2 mdeslaur mdeslaur 4096 Jun 18 10:40 evolution-mdeslaur-VMPrqC
drwx------ 2 mdeslaur mdeslaur 4096 Jun 18 11:14 evolution-mdeslaur-wrcl0C
-rw-rw-r-- 1 mdeslaur mdeslaur 5 Jun 18 11:13 spamd-pid-file-Y2CYFW
srw-rw-rw- 1 mdeslaur mdeslaur 0 Jun 18 11:13 spamd-socket-path-UZCYFW

This is after opening an attachment at 13:43:
mdeslaur@mdlinux:~/.cache/evolution/tmp$ ls -al
total 16
drwxr-xr-x 4 mdeslaur mdeslaur 4096 Jun 18 13:43 .
drwx------ 6 mdeslaur mdeslaur 4096 Apr 10 2011 ..
drwx------ 2 mdeslaur mdeslaur 4096 Jun 18 12:49 evolution-mdeslaur-PlMVtk
drwx------ 2 mdeslaur mdeslaur 4096 Jun 18 13:43 evolution-mdeslaur-ws2Jh2

See downstream bug report:

https://bugs.launchpad.net/ubuntu/+source/evolution/+bug/1014763