Removed security/ruby-soauth and security/ruby-roauth.

No package depend on those packages and no advantage to maintain pure ruby
gem with pkgsrc.
Drop maintainership, not using anymore.
Removed textproc/ruby-xmlscan.

Nothing depend on this package anymore and dead upstream.
Drop maintainership, not using anymore.
Removed net/ruby-tweetstream.

No package depend on this one anymore, and no advantage to maintain pure ruby
gem with pkgsrc.
Removed www/ruby-httpclient.

No packages depend on this one anymore and no advantage to maintain pure ruby
gem with pkgsrc.
Really remove ruby-xmlscan (hi obache)