Update core image on cache.lewiscounty.com

[forhire]

Updated the core image on our cacheflow server to 4.1.12 and it has resolved the slowness issue we encountered with some web sites, namely http://www.seattletimes.com/

We will be re-enabling WCCP support once we're confident the update is working as expected.

[forhire]

Re-enabled caching on all outbound serial interfaces. It appears to be working well.