update to Bundler 1.2.2
update changelog
upgrade to bundler 1.3.0.pre.2
update changelog
update the buildpack version :(
update changelog
bump version to v44
enable invoke dynamic on JRuby by default

@headius told me that the only known issues are when jruby is being
called directly from java and in a container. Seeing we aren't doing
that, we can enable this.
remove setting config vars in release
bump to v45
update changelog
override $GEM_PATH in .profile.d/ruby.sh

we need to be able to change $PATH and $GEM_PATH to be able to let users
change rubies seamlessly on the same app.
update changelog
install bundler binstubs into a different dir

This fixes #52.
symlink bundler binstubs in bin/ for backwards compatability

will not override bins that already exist here since they be put there
by the user
rbx2 doesn't need a build ruby
ruby naming scheme doesn't start with ruby engine
bump to v46
Rails3.use?: use String#include? instead of =~

closes #53
fix building ruby-build rubies