Create cashew log directory from pre-start stanza in upstart script.

Create cashew log directory from pre-start stanza in upstart script.

BUG=chromium-os:5253
TEST=Stop cashew (sudo /sbin/stop cashew). Delete log directory (sudo rm -rf /var/log/cashew). Start cashew (sudo /sbin/start cashew). Observe that log directory has been created. Restart cashew (sudo /sbin/restart cashew). Observe that existing log directory has not been disrupted.

[Vince Laviano, 2010-07-30 22:31:26]

This is one of a pair of CLs (along with
http://codereview.chromium.org/2883048/show) that moves cashew log directory
creation from its ebuild to its upstart script. This is necessary, because
/var/log is on the stateful partition where the ebuild cannot write.

PTAL.

[adlr, 2010-07-30 23:20:11]

LGTM