rails 4 and related deps

currently not all rails-related dependencies have bumped new versions
to rubygems. therefore i included the git sources. this has to be
reverted taking our .gemspec file into account.
rails 4 config templates
dependency updates
.model_name returns no string anymore
temporarily fixing duplicate root definitions
use already present @template
fix deprecation
merge master
fix superclass mismatch bugs introduced by rails 4
fix deprecations
merge master
no need to test rails core functionality
all tests green on rails 4
smash deprecations
run bundle install under jruby
bump rails in gemspec
bump sass-rails in gemspec
add protected_attributes to gemspec
lock bootstrap-sass to 2.x
embrace rails 4 api changes in path class