[CHEF-4117] fix resource attempting to remove constants it doesn't have

Module.const_defined?() needs to be given an optional second argument to
disable constant lookups on ancestor classes. Otherwise LWRP creation
may attempt to remove a constant that does not exist.
Merge branch 'CHEF-4117'
added explicit require 'chef/exceptions'
Merge branch 'master' of git://github.com/opscode/chef into CHEF-4114