Add references to CLA and Redmine. fixes #299
added an additional line to the help output for the model slice that shows the syntax for
getting the list of model templates (for some reason, this usage line was missed when we
refactored the slice API last August/September)
fixed copy-and-paste error in the line just added to the model help syntax
(#299) Add reference to trivial patch exemption.
Merge pull request #313 from khussey/documentation/master/299

Add trivial patch exemption, CLA, and Redmine references to contribution guide. fixes #299
Merge pull request #312 from tjmcs/tb/fix-model-help

Adds missing line to the model slice's help output