The Ptolemy II installer version should have an automatic update facility

[cxbrooks]

Note: the issue was created automatically with bugzilla2github tool

Original bug ID: BZ#523
From: @cxbrooks
Reported version: 9.1.devel
CC: pt-dev@chess.eecs.berkeley.edu

[cxbrooks]

It would be nice if the Ptolemy II installer would check for updated jar
files.

The most robust way to do this would be to supply OSGi jar files and
use a facility similar to how Eclipse works.

There would need to be a notion of a blessed version of the jar
files on a server and a way to get the jar files from the head.

Any update facility should use an update framework that is defined
elsewhere, we should not roll our own.

Note that WebStart provides an update facility that could be useful.