developed data model
using the new datamodel in read and write. Reading problem at first event!
print functions for Collections, and first utility functions
Jet and vector utility functions used in write and read
new utility functions. < operator for handles.
added first version of a dummy multijet event generator
CollectionBase pointers now registered in Registry. Changed writer interface

Allows the Writer to use the registry to get a pointer to the CollectionBase,
in order to branch the output tree.
Maybe not fully working yet for on-demand reading.
Merge pull request #13 from cbernet/coll_in_registry

Coll in registry