Updated README.md

Fixed install instructions, ruby 1.9.3-p395 does not exist, replaced by ruby 1.9.3-p429
Merge pull request #45 from fesplugas/patch-1

Updated README.md
Homebrew merged ruby-install formula.
Renamed --skip-install-deps to --no-install-deps for consistency.
Renamed a test.
Added the --no-verify option.
Updated the man pages
Updated the usage.
Omit period in usage.
Quote more arguments.
Style.
Moved defaults to the top of functions.sh.
Moved RUBY_ARCHIVE and RUBY_SRC_DIR into the individual functions.sh.
Moved the defaulting of RUBY_MD5 into load_ruby.
Set RUBY_MD5 after RUBY_ARCHIVE is properly set.
Added the --url option (closes #29).
Updated the man pages
Capitalize Ruby.
Added --no-download.
Updated the man pages