Fleshing out TTP model

Note: this work was done by Curt Beckmann with Colin Dixon merely fixing some
whitespace and formatting issues.

1.) Added some missing slugs
2.) Renamed Variables to Identifiers per the spec
3.) Added unversal-ttp-properities grouping for things every TTP node can have
4.) Reordered the top-level slugs in the model to match the spec

Change-Id: I75009d9212c5891384e13ccbe4043a68bd46bf37
Signed-off-by: Curt Beckmann <beckmann@brocade.com>
Signed-off-by: Colin Dixon <colin@colindixon.com>