add rbx-2.5.2

This is to fix the error when installing new gems that have executables
which match existing binstubs in the Rubinius bin directory:

    "bundle" from bundler conflicts with PREFIX/gems/bin/bundle

RubyGems is supposed to override the binstub if it detects that the
previous one was also generated by RubyGems for the gem of the same
name, but its detection mechanism gets thrown off by having a double
shebang as a result of our binstubs fixing process.

https://github.com/rubygems/rubygems/blob/v2.2.2/lib/rubygems/installer.rb#L149-L154

This avoids generating binstubs with a double shebang.

add rbx-2.5.1

When generating SHA2 checksums with `openssl`, we want to give
preference to the newer OpenSSL that might have been installed with
Homebrew. However if there's no `brew` command the ERR trap will kick in
and display the "BUILD FAILED" notice although the build would proceed
to run.

Related: c0dc8908

Fixes #713

Handles output like:

    Picked up JAVA_TOOL_OPTIONS: -javaagent:/usr/share/java/jayatanaag.jar
    java version "1.8.0_31"

Fixes #710

Fix JRuby 9.0.0.0-pre1 definition

Add JRuby 9.0.0.0.pre1

Upgrade openssl-1.0.1l

mruby 1.1.0 was released

See the [annoucement](http://www.mruby.org/releases/2014/11/19/mruby-1.1.0-released.html).

Upgrade openssl-1.0.1k

Closes #664, closes #682

Prior to this we tried to use pre-built LLVM binaries since Yosemite,
but starting with Rubinius 2.3.0 this is no longer a feature of its
build system. Instead, look for "llvm" Homebrew package and suggest
installing it if it's missing.

Add Ruby 2.3.0 dev definition

Closes https://github.com/sstephenson/ruby-build/issues/689.

Added definition of Ruby 2.2.0

add jruby-1.7.18

Add definition of Ruby 2.2.0-rc1

Final dist filename change for JRuby 9000.

Add jruby-1.7.17