add bugzilla integration hook. example of writing hook in python. hook updates bugzilla bugs when it sees commit comments that mention bug id, such as "i fixed bug 77". only bugzilla 2.16 supported yet, but easy to extend. bugzilla versions have different schema, i have not used later than 2.16.

Is there an error message when trying to diff non-existing files?
found: No such file or directory
not: No such file or directory
Is there an error message when trying to add non-existing files?
found: No such file or directory
not: No such file or directory