Include MessageExtractor code in fulltext

[giampaolo]

MsgExtractor lib is not easy to deal with in terms of packaging and as a dependency in general, see:

https://github.com/mattgwwalker/msg-extractor/issues/23
https://github.com/mattgwwalker/msg-extractor/issues/24
https://github.com/mattgwwalker/msg-extractor/issues/25

I even disabled travis CI for python 2.7 because it could not get installed:
2b01185

With this PR I just include it in fulltext code base. This will make builds faster as it's one less dep to retrieve from GIT (there's no MsgExtractor on PYPI).

[btimby]

Why not just fork and add to PyPI?

[giampaolo]

I'm not the owner so I cannot register MsgExtractor on PYPI. I filed a couple of issues on MsgExtractor bug tracker asking if they're interested in packaging it properly and put it on PYPI (they are). I made an initial PR but it's not reviewed/merged yet. Basically we can't properly fix this until they push it forward.

[giampaolo]

See:
https://github.com/mattgwwalker/msg-extractor/pull/26/files
TeamMsgExtractor/msg-extractor#23
TeamMsgExtractor/msg-extractor#25

[TheElementalOfDestruction]

Have your issues been fixed in the most recent version of msg-extractor?