* Require in Makefile that everyone use bundle to remove inconsistencies
* Require in Gemfile that everyone use Jekyll 1.3.*
* Require in Gemfile that everyone use Ruby 2.0.0 (already used by
Travis and most developers)
* Remove workaround _plugin/svg.rb which showed SVG files in `jekyll
serve` (fixed in Jekyll 1.0.0)
* Remove inconsistent file path workarounds in _plugins/autocrossref.rb
and _plugins/inline-template.rb