Added Object#metaclass helper.
Added Object#metaclass helper.

opal/mspec,elia/mspec,kachick/mspec,Zoxc/mspec,mkb/mspec,nobu/mspec,ryoqun/mspec,opal/mspec,MagLev/mspec,shirosaki/mspec,timfel/mspec,Gibheer/mspec,MagLev/mspec,ryoqun/mspec,kachick/mspec,rdp/mspec,rubinius/mspec,alex/mspec,eregon/mspec,iainbeeston/mspec,ruby/mspec,mrkn/mspec,shugo/mspec,iainbeeston/mspec,ruby/mspec,voxik/mspec