Added quick links section to README.

* Javadoc now more accessible.  (Finn complained.)
Updated feature status table in README.

* Statuses are now more detailed/accurate.
* Added Java CLI.
Switched order of quick links and downloads sections in README.
Improved javadoc portability of makefile.

* Added guard to patching Javadoc so that it will not be attempted for
  Javadoc content without the bug, i.e. Javadoc versions prior to 7.
  Tested with javadoc 1.6.0.