Add 'cd -' to proposed steps to upgrade ruby-build

When a target is not found, rbenv-install proposes pulling changes from
upstream. This involves changing the directory to the ruby-build checkout.

This patch adds a '&& cd -' to change the working directory back to where
we've been. Should work on at least Bash and Zsh.

Add 2.2.2, 2.1.6 and 2.0.0-p645 but they work

See https://github.com/sstephenson/ruby-build/pull/733 to get the joke.

Upgrade openssl-1.0.1m

added definition of Ruby 2.2.1

Rename jruby-9.0.0.0-pre1 to jruby-9.0.0.0.pre1

So the installed ruby version will match what is used in `.ruby-version` files

added definition of ruby 2.0.0-p643

removed jruby-9000 definitions

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