Added discover method to Bundle.
Added discover method to Bundle.

Use with caution as it can take a while to find members and if a
KeyboardInterrupt occurs, can cancel the writeout. We need to address
this, and perhaps write out to a hidden file followed by a move as a
simple safety net.

datreant/datreant,datreant/datreant.core,dotsdl/datreant,datreant/datreant.core,datreant/datreant