corrected bug in unit test

per [ralph's review](/siq/mesh/pull/23#issuecomment-13311086)

...so much for red green refactor...
clarified test case name

per [ralph's review](/siq/mesh/pull/23#issuecomment-13311086), bullet #4
fixed model test case name

per [ralph's review](/siq/mesh/pull/23#issuecomment-13311086), bullet #3
clarified model.js test case comments

per [ralph's review](/siq/mesh/pull/23#issuecomment-13311086), bullet #4

pertains to #15
added unit tests for model.set w/ noclobber: false

per [ralph's review](/siq/mesh/pull/23#issuecomment-13311086), bullet #6