add trigger support for collxml shedding: collection.xml is a magic name
make it possible to delete an entire collection tree
Move shred_collxml to schema directory.
This is because the shred_collxml file contains schema for functions and triggers. The python file has been moved there as well, because it has no better place to go at this time (so keep them together).
Include the shred_collxml definition in the initdb function.
Merge pull request #6 from Connexions/derived-collxml

Derived collxml + trigger and inclusion in database initialization code