Log Message:
Update graphics/ruby-gnuplot to 2.3.4.

* Use lang/ruby/gem.mk instead of misc/rubygems/rubygem.mk.
* Add LICENSE.
* Remove default value of GEM_BUILD.

2.3.4
 * Include more files in the gem by switching to Jeweler (thanks Jeweler guyz)!

2.3.3
 * Fix issue #4 (thanks Jakobs)
 * Fix some unit tests (thanks Nobu!)

2.3.2 Feb 2010
 * Add an arbitrary_lines specifier

2.3.1 Feb 2010

* Fix a bug I introduced in 2.3.0

2.3.0 Feb 2010

* incorporate a few patch changes

2.2.3.1 July 18 2009

* output the raw "to gnuplot" data if $VERBOSE

Version 2.2.2 July 2009

* raise if no executable found, should be windows compat. now