Add rbx-2.2.9, 2.2.8 was skipped due to broken wrappers.
Merge pull request #583 from keltia/rbx-2.2.9

Add rbx-2.2.9, 2.2.8 was skipped due to broken wrappers.
add jruby-1.7.13
Merge pull request #591 from neojin/jruby-1.7.13

add jruby-1.7.13
Add rbx-2.2.10
Merge pull request #595 from mkroman/master

Add rbx-2.2.10
ruby-build 20140702
Add link to suggested build environment to README
Merge pull request #603 from wjordan/patch-1

Add link to suggested build environment to README
Add test for ruby-build definitions
Support changing RUBY_BUILD_ROOT

This is to allow specifying an alternate path where `share/ruby-build/*`
definitions reside. Useful in tests as well.
Extra definitions paths via RUBY_BUILD_DEFINITIONS

This is a colon-separated list of directories that will get searched for
build definition in order from left to right.
Merge pull request #613 from sstephenson/definition-paths

Support extra definitions paths via RUBY_BUILD_DEFINITIONS

Closes #609
Merge remote-tracking branch 'sstephenson/master'

* sstephenson/master:
  Extra definitions paths via RUBY_BUILD_DEFINITIONS
  Support changing RUBY_BUILD_ROOT
  Add test for ruby-build definitions
  Add link to suggested build environment to README
  ruby-build 20140702
  Add rbx-2.2.10
  add jruby-1.7.13
  Add rbx-2.2.9, 2.2.8 was skipped due to broken wrappers.