WIP: Bump pom-imagej to 2.12

This updates the version of scripting-java to the 0.2.0 release, which
contains the new JavaRunner plugin type that we need.
Add a JavaRunner for ImageJ 1.x plugins
Switch to non-deprecated ij1-patcher classes

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
LegacyJavaRunner: Handle PlugInFilter, too

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
LegacyJavaRunner: make it work

Unfortunately, we cannot simply hand off to the LegacyService to run
the legacy command because the class is most likely not known to the
PluginClassLoader of ImageJ 1.x.

For now, let's punt and run the class directly (as we used to do in
Fiji's Refresh_Javas plugin). To allow compiling & running classes
that might be known to the PluginClassLoader, we will most likely
jump through hoops. That's next.

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