Add a convenience method to handle NoSuchMethodErrors

These errors are a strong indication of class path problems, i.e. one
class path element shadowing a newer class path element's classes.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Handle NoSuchMethodErrors in plugins

There are two ways to call plugins in ImageJ 1.x: the regular mechanism
calls IJ.run() -- which we intercept to support the Fiji's Command
infrastructure that was not accepted upstream but that is used by
some Fiji components -- and IJ.runUserPlugIn() -- which is called
e.g. by HandleExtraFileTypes.

This commit adds intercepts for NoSuchMethodError, looking closely
whether there are class path problems.

The idea came to this developer while looking at the n'th loci_tools.jar
issue: http://fiji.sc/bugzilla/show_bug.cgi?id=542

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Handle NoSuchMethodErrors also in .java 'scripts'

Our own on-the-fly compilation of .java files in ImageJ.app/plugins/
can face the same class path issues (where multiple class path
elements contain incompatible class versions) as regular plugins,
so we need to handle that, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>