- modify websites admin UI, API to add a column Exclude IPs
- IPs contain wildcards, unlimited IPs per website
- below the website table, added a "Global IP exclude" list. Ips there are excluded from all websites automatically.
- IPs are stored in the tracker cache file for fast access at Tracking time. 
- added new field in website table "excluded_ips"
- refactored the ajax loading/error display to allow multiple loading/error div per page 


git-svn-id: http://dev.piwik.org/svn/trunk@1970 59fd770c-687e-43c8-a1e3-f5a4ff64c105