Add Python 3 support

Fix external entities vulnerability #35

Upgraded xmltramp to 2.18 with some inline patching.
Experimenting with Travis-CI integration.

Corrected regression bug in xmltramp when updating to new style classes. Fixes issue 26.

Address type marshalling to Dict. PEP8 cleanup. New-style exception classes.

Added logout and sendEmail implementations. Brought readme and changelog back into sync.

This has the same commits as the pypi 1.5 release, but wasn't published on github correctly at the time.

Contains code for sendEmail implementation.