switches global setting var to be a constant var - refs #100

Fixes #111 - GW::puppetca#clean now logs an error and fails when there in no CA

Fixes #74. Logger messaging works in the proxy module

A logger method was introduced as well as a mechanism for logging if this
code is run as a standalone cgi service

added active_scaffold_list_filter plugin

fixes #74 - tftp and puppet ca errors are not shown in the log file

added some basic error handling

added act_as_audited plugin, seems to be a better implementation than our onws

reverted to an older AS commit

AS had a bad commit, reverting - see http://code.google.com/p/activescaffold/issues/detail?id=711&colspec=ID%20Type%20Status%20Summary

updated AR version