Fix Metabolics Tutorial to use files in distribution

[jimmyDunne]

Tutorial for Simulation Based Design to Reduce Metabolic Cost uses a downloaded package from SimTK. The example should use files from the distribution.

This PR requires (i) changes to the Confluence Documentation, and (ii) updates to the Models repo to ensure that tutorial functions as expected.

[jimmyDunne]

NOTE: Need to decide on where the metabolic scripts are going to come from. The version in the distribution comes from the GUI repo, but copies are here in the models repo.

[chrisdembia]

We should discuss that in the daily sprint today.

[jenhicks]

Need someone to review the doc and example once we have a build with everything in it.