Add Pattern Matching to eccollect command

[matthewwithanm]

It would be nice if the command accepted a list of file patterns to collect. For example:

./manage.py eccollect *.js
./manage.py eccollect path/to/my/file.js

We should also consider a syntax for specifying apps

./manage.py eccollect myapp:*.js
./manage.py eccollect myapp:*

Although that may not be possible/desirable given the fact that the AppDirectoriesFinder abstracts the app location away.