Merge pull request #53 from zmalltalker/master

When running ruby-install as root, don't prefix $package_cmd with sudo
Style.
Always run brew as owner of brew binary.
Merge pull request #54 from havenwood/brew

Support `sudo ruby-install` with brew on OS X.
Style.
Make comments more uniform.
Removed old code.
Fix --version short-option to correctly reflect -V.
Use command -v instead of type -t.
Add support for URLs as -p option values.

Try to download any patches specified via the -p option that start with
http or https and apply them.

So this example from README really works:

$ ruby-install -p https://raw.github.com/gist/4136373/falcon-gc.diff ruby 1.9.3-p429
Merge pull request #61 from bkutil/remote_patches

Add support for URLs as -p option values.
Should be an Array.
Set SRC_DIR and RUBY_SRC_DIR to use test/src/.
Avoid wordsplitting and path expansion of $PATCHES. (@zendeavor)
More quoting.
Swap path/patch variables.
Inline.
Spacing.
Download the patches into $SRC_DIR/$RUBY_SRC_DIR.
Split tests into two files.