Update share/ruby-build/rbx-2.0.0-dev

Rbx 2.0.0-dev need yaml install like rbx 2.0.0-rc1
Adding jruby-1.7.3
Merge pull request #292 from robertrolandorg/master

Adding in JRuby 1.7.3 support
Create 1.9.3-p392
Merge pull request #294 from sorah/193p392

Add 1.9.3-p392
ruby-build 20130222
Merge pull request #260 from shingara/patch-2

Update share/ruby-build/rbx-2.0.0-dev
Update examples to use latest MRI