Correct logic for mapController.map being undefined

Success path code assumes that map is always
created successfully.  If it is not (as per
changes made in 83b16cd1009750a4a0) we should not
try to manipulate the map object.
Merge pull request #77 from tiger-swallowtails-2014/fix-mapController.map-existence-assumption-bug

Merging to master as per Steven