Prefer ggrep for grep invocations that use GNU extensions.
Merge pull request #554 from LawnGnome/solaris-grep

Prefer ggrep for grep invocations that use GNU extensions.

Fixes ruby-build on Solaris 11.1
ruby-build 20140420
Correct the JRuby 9000 snapshot directory name.
Make the downloading message print the actual file name, not just the package name plus .tar.gz.
Merge pull request #559 from chrisseaton/fix-jruby-9000-package-name

Correct the JRuby 9000 snapshot directory name.
Merge pull request #560 from chrisseaton/downloading-filename

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