OpenJDK instead of Oracle's Java in the docs

Hi,

In the Electric documentation[1], the user is advised that Oracle's Java
1.6 is required to run the program. However, Oracle's Java
implementation is proprietary software. Meanwhile, OpenJDK is a free
implementation that is mature and seems to be fully capable of running
the program (at least based on my rudimentary testing).

I think that, since Electric is a GNU program, it would be advisable to
change to recommending OpenJDK as the requirement in the manual.

Cheers,
Brandon Invergo


[1] http://www.staticfreesoft.com/jmanual/mchap01-03.html