Spec dash behaviour for padded format directives.
Spec dash behaviour for padded format directives.

Following JRuby issue https://github.com/jruby/jruby/issues/289, it appears
MRI applies '-' to normally padded format directives.  This added spec
documents this behaviour.

yaauie/rubyspec,sgarciac/spec,nobu/rubyspec,iainbeeston/rubyspec,amarshall/rubyspec,agrimm/rubyspec,mrkn/rubyspec,wied03/rubyspec,jstepien/rubyspec,BanzaiMan/rubyspec,nevir/rubyspec,eregon/rubyspec,josedonizetti/rubyspec,benlovell/rubyspec,Aesthetikx/rubyspec,bl4ckdu5t/rubyspec,Aesthetikx/rubyspec,JuanitoFatas/rubyspec,scooter-dangle/rubyspec,yb66/rubyspec,DawidJanczak/rubyspec,mbj/rubyspec,ruby/spec,jannishuebl/rubyspec,ericmeyer/rubyspec,jannishuebl/rubyspec,askl56/rubyspec,teleological/rubyspec,amarshall/rubyspec,ruby/spec,ruby/spec,kachick/rubyspec,kidaa/rubyspec,jstepien/rubyspec,chesterbr/rubyspec,DavidEGrayson/rubyspec,eregon/rubyspec,josedonizetti/rubyspec,lucaspinto/rubyspec,DavidEGrayson/rubyspec,yous/rubyspec,JuanitoFatas/rubyspec,ericmeyer/rubyspec,kachick/rubyspec,sgarciac/spec,nevir/rubyspec,saturnflyer/rubyspec,askl56/rubyspec,DawidJanczak/rubyspec,nobu/rubyspec,ruby/rubyspec,agrimm/rubyspec,jvshahid/rubyspec,wied03/rubyspec,saturnflyer/rubyspec,jvshahid/rubyspec,yous/rubyspec,yb66/rubyspec,bl4ckdu5t/rubyspec,bomatson/rubyspec,BanzaiMan/rubyspec,bomatson/rubyspec,iainbeeston/rubyspec,sgarciac/spec,sferik/rubyspec,mbj/rubyspec,kachick/rubyspec,benlovell/rubyspec,iliabylich/rubyspec,atambo/rubyspec,lucaspinto/rubyspec,eregon/rubyspec,yaauie/rubyspec,alexch/rubyspec,wied03/rubyspec,nobu/rubyspec,teleological/rubyspec,mrkn/rubyspec,iliabylich/rubyspec,atambo/rubyspec,ruby/rubyspec,sferik/rubyspec,alexch/rubyspec,scooter-dangle/rubyspec,kidaa/rubyspec,chesterbr/rubyspec,markburns/rubyspec,markburns/rubyspec