Add to stable branch. Fix a bug with fax_success in a few places it was set to numeric 0 but used in an IF statement as a string. Fax retry worked in many situations but this bug prevented it from working all the time. 

git-svn-id: http://fusionpbx.googlecode.com/svn/trunk@5127 e2954ef0-caed-11de-bd98-e341d93cc3cc