Mark plugins as legacy-incompatible

This change makes sure that ImageJ's upcoming LegacyUI does not override
legacy commands with our commands of the same name.

Performed using the shell commands:

sed -i '' -e \
'/^@Plugin/,/^public class/s/)$/, attrs = { @Attr(name = "no-legacy") }&/' \
-e 's/import org.scijava.plugin.Menu;/import org.scijava.plugin.Attr;\
&/' $LIST

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'no-legacy'

This topic branch is part of the multi-repository effort to mark
a couple plugins as incompatible with the LegacyUI.

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