macros properly handle empty case classes

warning: this means one empty parameter list. case classes without
parameter lists are deprecated and not supported by macros
macros handle singletons
new macro option: AllImplementations
small addition to README
Fixes issue #78
ignore .plugins.sbt (for local plugins), update to sbt-0.12.4, sbt-idea-1.5.1
update to akka-2.2.1, play-2.2.0-RC1.
bump version, too. (don't beat me if it's wrong)
get back the Publish.settings (publish-local did not work with it): I guess, it does have a certain purpose ;)
Merge pull request #108 from imikushin/akka-2.2.1-play-2.2.0-rc1

Akka 2.2.1, Play 2.2.0-RC1
Merge pull request #103 from akkie/master

Fixes issue #78
Merge pull request #92 from edofic/macros

more macro magic
Merge pull request #95 from jeffling/master

minor addition to README
Merge pull request #1 from ReactiveMongo/master

forward to upstream/master