Fixed RDoc title.
Use a configure task and an extension task to build ruby-edje. Note that I had to edit extensiontask.rb to include sitearchdir so that the ruby-evas headers would be picked up.
Added a publish task.
Added an RDoc task.
Removed RCS-style IDs.
Create target directory if it doesn't exist yet.
Added support for RUBYARCHDIR.
Reworked the build system.