Merge pull request #835 from jemc/master

Problem: zhash key type is const char *, but zhash_cursor type isn't
Problem: Missing feature to export UUID as fomatted string in canonical form (8-4-4-4-12)

Solution: Added a method zuuid_formatted_str to export the UUID string in canonical form
Merge pull request #837 from oikosdev/master

zuuid: proposed a feature to export UUID in their canonical form
Problem: Selftest for zhash leaks memory
Solution: Destroy the hashes that are created
Problem: Code for zuuid_formatted_str is not quite idiomatic
Solution: Return a freshly allocated string instead (and adjust whitespace)