Removed a warning message from automation log

We log a warning everytime a service model is not found. Which includes
basic ruby objects. e.g.
[----] W, [2014-06-20T13:01:03.092624 #3049:3fe521833bdc]  WARN -- :
Service Model string not found
Merge pull request #84 from mkanoor/noise_in_log

Removed a warning message from automation log
Moved enable/disable download buttons code to a generic method.

Changed code to enable/disable Download buttons on Reports tab in Utilization explorer. Buttons were not getting enabled/disabled based upon result data when user sent up tree_select transaction while user was on Reports tab. Existing code was only handling enable/disable of download buttons when switching tabs.

https://bugzilla.redhat.com/show_bug.cgi?id=1113062
https://bugzilla.redhat.com/show_bug.cgi?id=1114659