Session layer refactoring

Session layer refactoring

Major refactoring of the session layer api
- Add attatch api for application binding to the the session layer
- Simplify listen/connect calls
- Update application CLI
- Add transport endpoint to accept callback
- Associate segment manager to application and allow for multiple
  binds/connects per app

Additional:
- svm fifo cleanup
- add fifo free, format fns
- add fifo offset enqueue unit test

Change-Id: Id93a65047de61afc2bf3d58c9b544339c02065af
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dave@barachs.net>