Remove needless fallback fullscreen/unfullscreen

They don't support dual display. We can always use
fullscreen/unfullscreen that are provided by GTK+. They will always
work well. :-)

Reported by uwabami. Thanks!!!
theme lightning-talk-toolkit: Support as-large-as-possible slide property

You can use the property to change font size per slide.

Force enable:

  = Large Title

  == properties

  : as_large_as_possible
     true

Force disable:

  = Large Title

  == properties

  : as_large_as_possible
     false
rake: fix publish order

Stop a old URL of Rabbit Slide Show.

before: 1.rubygems 2.slideshare 3.speaker_deck
after: 1.slideshare 2.speaker_deck 3.rubygems
rake gem: fix NameError for RubyGems 2.0

Changed a sentence of gem build in RubyGems 2.0.

1.8: Gem::Builder.new(spec).build
2.0: Gem::Package.build(spec)
indent
Add Rabbit::GemBuilder

It deals with incompatiblities between RubyGems on Ruby 1.9.3 and Ruby
2.0.0. They provides different API for creating .gem from .spec.