handle objects which respond to to_html and to_latex
handle objects which respond to to_html and to_latex

domitry/iruby,SciRuby/iruby,astroboxio/iruby,jjn2009/iruby,hainesr/iruby,Rambatino/pi-ruby,SciRuby/iruby,Sharpie/iruby,domitry/iruby,jjn2009/iruby,zalt50/iruby,astroboxio/iruby,mijoharas/iruby,zalt50/iruby,hainesr/iruby,Sharpie/iruby,SciRuby/iruby,zalt50/iruby,mijoharas/iruby,zalt50/iruby,Rambatino/pi-ruby,SciRuby/iruby