Merge branch 'release/4.0.0' into develop
fix for rubinius 2.0.0.weekly (1.8.7 release 2013-04-26 JI)

can't delete an element from an array inside the each block
add version command
refactor warnings

warning is a hash with a :message key
add file path to warnings
use xpath notation in warning messages
format warnings listing
prepare release
Merge branch 'release/0.0.5'