Log Message:
Update www/thoth to 0.2.1.

* Use lang/ruby/gem.mk instead of misc/rubygems/rubygem.mk.
* Add LICENSE.
* Remove default value of GEM_BUILD.
* Update dependency according to gemspec.
* Add CONFLICTS since it will install the same name commands both
  ruby18 and ruby19 based packages.

Exact changes are unknown.