General Additions To Node Setup

Hi Henrik,

This is the first feature branch according to our email exchange on Sept 16.  These additions are fixes that should benefit any node (i.e. not cloud scheduler or cernvm specific).  To arrive at this branch I forked your current master and cherry picked commits from my spiiphrebase branch (containing my original modifications rebased to your current master). To make my changes easier to digest I've concatenated my commits into five commits each addressing one specific topic.

##### Network Optimization
The first commit ( 3cbb3c5 ) adds the network optimization (as according to [ESnet's fasterdata] [1]).

##### System Clock
Commit 101221c ensures that the VM system clock is set to UTC.

##### cvmfs Configuration
Commit caa0356 adds configuration options to the cvmfs module including an option to set the cvmfs server priority.

##### Condor Configuration
Commit 8a4eb37 addresses issues we encountered while getting the condor clients up and running on the virtual machines.

##### Grid Environment
The last commit ( 7b390f1 ) brings the grid environment in line with what is used on the tier2's.  The addition of VO_ATLAS_SW_DIR was essential to allow pilot jobs to set-up atlas software.

[1]: http://fasterdata.es.net/host-tuning/linux/ "ESnet's fasterdata"