added definition of 1.9.3-p547

This reverts commit d45f1451, reversing
changes made to 13de5110.

Added definition of 2.0.0-p481

Ruby 2.1.2 is released!

link the latest log to /tmp/ruby-build.latest.log

Make the downloading message print the actual file name, not just the package name plus .tar.gz.

Correct the JRuby 9000 snapshot directory name.

Prefer ggrep for grep invocations that use GNU extensions.

Fixes ruby-build on Solaris 11.1

Adding JRuby 1.7.12

OpenSSL library updated to 1.0.1g

Previous versions of the library contain a vulnerability CVE-2014-0160.

Link to releases in the Readme

Stop maintaining the changelog

All releases information has been migrated to GitHub Releases:
https://github.com/sstephenson/ruby-build/releases

This frees core contributors from having to maintain release notes in version
control, and regular contributors from wondering whether they need to edit
CHANGELOG while submitting a pull request.

Benefits of release notes being outside of version control are that they can be
edited post-release.

Seems like sed 4.1.5 on RHEL 5.3 doesn't support `-E`, and sed on OS X doesn't
support `-r` to activate the extended regexp mode. Best to avoid extended regexp
altogether for compatibility.

Fixes #495

References #433

2.0.0-p451 should use libyaml-0.1.6 too

The `-f` option allows for forcing installation of versions that already
exist in the environment. If that option isn't used, then an interactive
prompt is created which causes problems for non-interactive execution of
the command.

This change adds the `-s/--skip-existing` option to not install versions
that already exist, while still exiting as success.

Closes #543

Update libyaml to 0.1.6

link the latest ruby-build.$SEED.log and ruby-build.$SEED/ to ruby-build.latest.log and ruby-build.latest/ respectively

Security fix for CVE-2014-2525

Advisory: http://www.ocert.org/advisories/ocert-2014-003.html