Try to import external localflavor library

This will allow the package to work with users of Django 1.6 who have installed the recommended/spun-off external localflavor library
Adjustments to localflavor import

preferring external localflavor, and narrowing the exception catching
Merge pull request #36 from mjacksonw/master

Try to import external localflavor library (Django 1.6 compatibility)