choose packages/services appropriately based on $operatingsystem

Hello Garrett!

I tried deploying your nfsclient module on RHEL5 and Ubuntu 10.04 LTS, and in each case I ran into errors due to nonexistent package names or service names.  Please consider accepting this patch, which includes updated names that provide the desired result on each of these platforms (and, I expect, others as well).

Please feel free to ignore my alteration of the module name; that was just for ease of testing.

thanks,  
-Steve