Added additional attribute parsing and corresponding unit-tests.
E-mail attachment and url extraction added in this commit. This includes
unpacking zipfiles and simple password cracking of encrypted zipfiles.
This email meta-data import module collects basic meta-data from an e-mail
and populates an event with it. It populates the email subject, source
addresses, destination addresses, subject, and any attachment file names.
This commit also contains unit-tests for this module as well as updates to
the readme. Readme updates are additions aimed to make it easier for
outsiders to build modules.