rename jarfile to jcdf.jar
Remove non-JCDF source files.

The files for STIL support of CDF, and the CEF-related files (also for
STIL support) have been removed, and will now be looked after inside
the starjava repository.  The remaining classes are only those required
for standalone CDF access.
Rename java package cdf.* -> uk.ac.bristol.star.cdf.*.

Verbose but correct.
Add implementation status section to document