Wrote some more documentation
Improved docs a bit more
Handle cases where the same parameter is specified multiple times

Fixes issue #22
No sense decoding duplicate param values
Added support for parsing dates that are all caps.

Apparently Oracle Email Server SDK 9.0.5 was written by
people who have never bothered to actually read rfc*822.

Fixes issue #23
Cleaned up the DateUtils code a bit
Merge remote-tracking branch 'upstream/master'