Initial experiment with Specs2
update core/common tests to use specs2
Changes to build files
lift-common
lift-actor
json, json-scalaz, json-ext
lift-util
lift-webkit
Remove MailerSpec hack, now that testMode checking is fixed in Props
lift-db, lift-mapper
lift-ldap
Fix Props.mode calculatation to work with specs2 concurrent test running

Note: this is needed by the last two commits (MailerSpec and
ResourceServerSpec)
lift-couchdb
lift-mongo (tests pass now)
lift-record
lift-mongodb-record
lift-squery-record
Add !< to LiftCometActor.

CometActor had the function by virtue of extending Lift's actor traits;
however, the LiftCometActor trait that is often used to reference it
didn't define that the method would be present. We add it there so it
can be referred to anywhere that LiftCometActor is passed around instead
of CometActor.

!< returns an LAFuture for a message reply.
Include a version on the end of the Ajax GUID.

AJAX requests currently carry a GUID. We now add a single-character
version indicator. This version increments for distinct AJAX requests.
In particular, it does NOT increment during AJAX retries, so that a
retry of an existing request can be identified as being part of the same
attempt on the server.

Not all AJAX requests carry this version identifier. In particular, Lift
GC requests do not carry a version identifier. This is because these
are going to be handled in a streamlined handler. If a Lift GC request
doesn't make it through, we can retry it as many times as we want and
it'll just remark stuff in the session.

liftAjax.addPageNameAndVersion appends both the page GUID and the
version number. The version number is encoded in base-36.
Rename continuation-related code to clarify Comet association.

We're about to add some AJAX-related continuation code, so we want it to
be clear the existing stuff is for comets.