NEW: Installation procedure

Included on this pull INSTALL.txt ( which contains the first draft of the installation instructions for RSS ).

RSS scripts re-done to be more user friendly and less buggy. Added:

dirac-rss-setup: ONLY to be used when "installing" RSS, it will create the DB tables for the ResourceStatusDB using their "pythonic" definition. This script should disappear on next revision. 

dirac-rss-list-status: dumps database into standard output so that users do not need to put their hands on MySQL to see what the status is.

FIXED:

dirac-rss-sync: updated to populate the DB correctly having on mind the new schema.
dirac-rss-set-status: cleaned old code calls.