Glass - Multiple File Generation POC

Manager.tt for managing multiple file outputs was borrowed and modified.
source:

http://damieng.com/blog/2009/11/06/multiple-outputs-from-t4-made-easy-revisited

Known Issues:
1. output path for generated files is currently written to file system
by the header template and and read in the item template. the first time
code is generated this may fail but it succeeds the second time.