Add LiftRules.supplementalHeaders and deprecate supplimental variant.

supplementalHeaders is now a FactoryMaker, whereas supplimentalHeaders was a
volatile var containing a generation function, though it had recently been
switched to point to the listOfSupplimentalHeaders FactoryMaker.
Bump us to sbt 0.13.1.
Liftsh is now smart enough to download the sbt launcher for you.
Ignore the sbt launcher jar under project/
Fix form element in MongoListField
Apply cursor conversion improvement to MongoMetaRecord.findAll
Fix: mail attachments should be placed in multipart/mixed MIME part.
Merge pull request #1564 from lift/tcn_issue_837

Apply cursor conversion improvement to MongoMetaRecord.findAll
Merge pull request #1533 from lift/spelling-bee

Spelling Bee: General spelling fixes + deprecations for 2.x series
Merge remote-tracking branch 'origin/master' into zero-point-thirteen

Conflicts:
	build.sbt
Start pulling the yui compressor plugin from git directly.
Somehow 2.10.0 ended up as the default version? Fixed.
Merge pull request #1563 from lift/tcn_issue_1551

Fix form element in MongoListField

Before, selecting 0 items would not properly update the field.
Bump sbt to version 0.13.5.
Some formatting improvements in Mailer.buildMailBody
Improve variable names a bit to improve readability.
Add a comment documenting behavior of Exchange w/ mixed.

We added this code because some Exchange servers don't play nice without
a mixed multipart. This appears to be tied to some versions of the
Exchange server, not neccicarily Outlook or other associated clients.
Add a spec to cover the new multipart/mixed behavior.
Remove a println.
Merge pull request #1537 from lift/zero-point-thirteen

Bump to sbt 0.13.5.