[sldev] Fix for SNOW-48 (Textures Not Resolving On Megaprims)

[Rob Lanphier]

Hi folks,

Bao attached a fix for SNOW-48 (Textures Not Resolving On Megaprims):
http://jira.secondlife.com/browse/SNOW-48

Patch:
http://jira.secondlife.com/secure/attachment/28755/bao-snow-48.patch

We'll commit this one soon unless there's some feedback to the
contrary.  It's been through a code review cycle here, but more eyes
are always better.  Please comment on SNOW-48.

Thanks
Rob