Use bower to manage dependencies
Fix bindToChangesInSourceModel when source_model is not an array

_.union in underscore < 1.7.0 wrapped non-array values into an array.
1.7.0 does not allow this, which breaks the binding of ViewModels to
their source models. Update the initialization of the
sourceModel variable to wrap an array around source_model so that we
enter the _.each loop properly.
Use memory safe listenTo to listen to source_model change events
Merge pull request #1 from UseAllFive/use-listenTo

Bring backbone-view-model to the future