POM: update to pom-imagej 2.6
POM: add used-but-undeclared dependency
LegacyImageJApp: fix priority

The ImageJApp priority changed to HIGH, so LegacyImageJApp needs to be
higher than that, now.
Remove legacy ImageJ app

This code migrated to the toplevel net.imagej:imagej component:
https://github.com/imagej/imagej/commit/2300d79ef55d9fd360bfda0c38713dbc64f55c65
Bump to pom-imagej 2.7

This also adjusts the code for the updated imagej-common 0.5.0.
Bump to next development cycle

Signed-off-by: Curtis Rueden <ctrueden@wisc.edu>
Add an interactive test for the legacy mode

This new test lets you start up ImageJ2 in legacy mode, for interactive
playing around and testing. You can execute it with

	mvn exec:java -Dexec.mainClass=imagej.legacy.TestDrive \
		-Dexec.classpathScope=test

or in Eclipse

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix tyop in Javadoc

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Use ImageJ2 logo in legacy mode

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
wip
fixup! wip
fixup! wip
WIP: update LegacyUI for new paradigm

Instead of creating anonymous inner classes for things like status and
toolbars, we could create adapters for the IJ layer.
wip: ActiveImagePlusPreprocessor

Provides a method to harvest ImagePlus @Parameter inputs.
WIP: LegacyCompatibleCommand

It was decided this should be a duck type class that does not extend
ij.Plugin.
WIP: status bar

add adapter status bar
wip: LegacyDialogPrompt
WIP: create toolbar adapter
WIP: create ApplicationFrame adapter
WIP remove IJ1 imports from all but IJ1helper