Use mutable Map for storing local actions

If multiple Ajax requests are submitted at once, they'll get independent
copies of the LocalActions map.  This may result in subsequent errors if
local actions created by e.g. the first request are used later in
combination with a snapshot created by a later request.
LocalActionRef should be a RequestVar, not ScreenVar

The lifetime of a ScreenVar may extend across multiple pages, but the
contents of this particular ScreenVar is inherently request scoped.
Local actions may cease working if the screen is restored from an old
snapshot.
Use mutable reference to immutable map
Squashed commit of the following:

commit aeb44de3bc42f86324a6242b6b8037dd4cb8fbc3
Author: David Pollak <feeder.of.the.bears@gmail.com>
Date:   Tue Mar 5 11:48:56 2013 -0800

    Squashed commit of the following:

    commit 24ff1d946cb1f80630e747a7793ba3f574fe7202
    Author: David Pollak <feeder.of.the.bears@gmail.com>
    Date:   Tue Mar 5 11:47:24 2013 -0800

        Removed external bcrypt depedency because the code is already in Lift

commit 09980e8263723f978784666d467e8256118d2446
Author: David Pollak <feeder.of.the.bears@gmail.com>
Date:   Tue Mar 5 11:32:01 2013 -0800

    MappedPassword now uses bcrypt, but is backward compatible with existing passwords and schemas
Memoization should not ingore type parameters. Fixes #1417.
Fix #1418 (problem with JSON unflatten when using common prefixes)
Merge pull request #1419 from obruchez/master

Fix #1418 (problem with JSON unflatten when using common prefixes)
Revert a fix for #1418. One test breaks
Revert a fix for #1418. One test breaks
Revert a fix for #1418. One test breaks
Fix #1418 (problem with JSON unflatten when using common prefixes)
Move lift-json-scalaz to Scalaz 7
* All tests pass, but only compiling for Scala 2.10.0 at the moment.
* May need a lift-json-scalaz7 subproject to provide both Scalaz 6 and Scalaz 7 support.
Adds lift-json-scalaz7 (Scalaz 7 support).
* Adds a new submodule for lift-json-scalaz7.
* Maintains lift-json-scalaz for Scalaz 6 support.
* Updated README to correspond to Scalaz 7.
Revert "Move lift-json-scalaz to Scalaz 7"

This reverts commit 765ae74a3cb318224ece66be3ffeff81271e34df.
Merge branch 'scalaz-seven'
Update contributors
Merge pull request #1424 from taylorleese/master

Adds lift-json-scalaz7 (Scalaz 7 support). Based on Joni's mailing list thumbs up, I'm applying the patch
Addresses a data bleeding issue with lift-json
join specs expectations with 'and'

Only the expectation returned in a spec is used for success/failure
evaluation. Multiple clasues must be and'ed to gether. Also, add some
naked expectations into proper specs in 'SerializationExamples' and
'LottoExample' so they are evaluated by the specs runner.
Optimization for LiftSession.findSnippetClass

snippet name to class map will be cached on the LiftSession object to
avoid duplicate searches. This is to a avoid a performance problem where
the searches become expensive as many snippet packages are added and the
number of classes loaded is very large.