Log Message:
Update rubygems package to 1.8.17.

=== 1.8.17 / 2012-02-17

* 2 minor enhancements:

  * Add MacRuby to the list of special cases for platforms (ferrous26)
  * Add a default for where to install rubygems itself

* 3 bug fixes:

  * Fixed gem loading issue caused by dependencies not resolving.
  * Fixed umask error when stdlib is required and unresolved dependencies exist.
  * Shebang munging would only take one arg after the cmd
  * Define SUCKAGE better, ie only MRI 1.9.2
  * Propagate env-shebang to the pristine command if set for install.

=== 1.8.16 / 2012-02-12

* 3 bug fixes:

  * Fix gem specification loading when encoding is not UTF-8. #146
  * Allow group writable if umask allows it already.
  * Uniquify the spec list based on directory order priority