Changes to the 'service list' commands for Identity v2 and v3:
* Document support for --long
* Add Description to v3 output with --long
* v3 output is now (ID, Name, Type), with (Description, Enabled) added with --long
* Change v2 output to match v3 output, with the absense of Enabled.
* Update doc to match
Closes-Bug: #1411337
Change-Id: I999e3df22f61350cdeba63bbb7d01145c2ffeeaf