add basic interface to create alert checkers and associations


git-svn-id: http://observium.org/svn/observer/trunk@4498 61d68cd4-352d-0410-923a-c4978735b2b8
add config entry for alerting and remove some debugging


git-svn-id: http://observium.org/svn/observer/trunk@4499 61d68cd4-352d-0410-923a-c4978735b2b8
add the ability to delete an alert checker. add pencil icon.


git-svn-id: http://observium.org/svn/observer/trunk@4500 61d68cd4-352d-0410-923a-c4978735b2b8