jEdit bootstrap classpath location.

There are occasions where plugins require jar files added to jEdit's classpath. The normal jEdit JarClassloader does not suffice in these circumstances as these jars need to be a part of the System classloader.

To fix this jEdit should have a well known location where jar files can be added, and have them be part of jEdit's system classloader. This can be a /lib, or /shared directory under the jEdit installation directory, or under the jEdit settings directory.

It would be nice if there was an interface within jEdit to install jars into this directory - a restart of jEdit would be OK in my opinion. There should be some way of doing this programmatically as well - perhaps jEdit.getSharedLibDirectory(). A plugin should be able to take jars from it's package and install them into this directory and ask the user to restart jEdit.