Log Message:
Update rubygems to 2.4.6.

* Simplify Gem::Specification definition.
* Remove some pkgsrc specific modifications.

=== 2.4.6 / 2014-02-05

Bug fixes:

* Fixed resolving gems with both upper and lower requirement boundaries.
  Issue #1141 by Jakub Jirutka.
* Moved extension directory after require_paths to fix missing constant bugs
  in some gems with C extensions.  Issue #784 by Andr«± Arko, pull request
  #1137 by Barry Allard.
* Use Gem::Dependency#requirement when adding a dependency to an existing
  dependency instance.  Pull request #1101 by Josh Cheek.
* Fixed warning of shadowed local variable in Gem::Specification.  Pull request
  #1109 by Rohit Arondekar
* Gem::Requirement should always sort requirements before coercion to Hash.
  Pull request #1139 by Eito Katagiri.
* The `gem open` command should change the current working directory before
  opening the editor.  Pull request #1142 by Alex Wood.
* Ensure quotes are stripped from the Windows launcher script used to install
  gems.  Pull request #1115 by Youngjun Song.
* Fixed errors when writing to NFS to to 0444 files.  Issue #1161 by Emmanuel
  Hadoux.
* Removed dead code in Gem::StreamUI.  Pull request #1117 by mediaslave24.
* Fixed typos.  Pull request #1096 by hakeda.
* Relaxed CMake dependency for RHEL 6 and CentOS 6.  Pull request #1124 by V«¿t
  Ondruch.
* Relaxed Psych dependency.  Pull request #1128 by V«¿t Ondruch.