add an option for filtering on regex not matching

git-svn-id: svn+ssh://svn.mozilla.org/sysadmins/svc/scripts/inventory@63874 65d70b31-241a-0410-a745-f8fa14660ae9
oops, i actually do want to includ httplib

git-svn-id: svn+ssh://svn.mozilla.org/sysadmins/svc/scripts/inventory@63875 65d70b31-241a-0410-a745-f8fa14660ae9
fix --set-field validation

git-svn-id: svn+ssh://svn.mozilla.org/sysadmins/svc/scripts/inventory@63876 65d70b31-241a-0410-a745-f8fa14660ae9
remove a testing function that snuck in

git-svn-id: svn+ssh://svn.mozilla.org/sysadmins/svc/scripts/inventory@63877 65d70b31-241a-0410-a745-f8fa14660ae9
make readme more complete, and add an example

git-svn-id: svn+ssh://svn.mozilla.org/sysadmins/svc/scripts/inventory@63878 65d70b31-241a-0410-a745-f8fa14660ae9