Upgrade to Ruby 1.9.3. [#66]
Merge branch 'master' into 66-ruby-1.9.3

Conflicts:
	.rvmrc
Upgrade to Ruby 1.9.3. [#66]
Update ZenTest to a version compatible with current Gem; switch debugger gem. [#66]
Update version number and changelog. [#66]
Merge branch '66-ruby-1.9.3'