crawlurls management command: enable-plugin option
crawlurls management command: enable-plugin option

This makes it trivial to enable plugins via the command-line: --enable-plugin=tidy, --enable-plugin=graph, etc.

ericholscher/django-test-utils,frac/django-test-utils,acdha/django-test-utils,acdha/django-test-utils,frac/django-test-utils,ericholscher/django-test-utils