(SERVER-102) Remove PUPPET_LOADED from Rakefile

Remove the PUPPET_LOADED environment variable from the Rakefile,
as it's no longer needed with the upgrade to JRuby 1.7.17.
(maint) address bit-rot in dev/user_repl.clj
(maint) bump version number to 2.0.0-SNAPSHOT
Merge pull request #334 from KevinCorcoran/bump-dat-shiz

bump version to 2.0.0-SNAPSHOT and a lil' cleanup
Merge pull request #333 from fpringvaldsen/SERVER-102-remove-PUPPET_LOADED

(SERVER-102) Remove PUPPET_LOADED from Rakefile