Move almost all ImageJ 1.x-specific stuff out of DefaultLegacyService

This hopefully helps some class loading problems... It's cleaner to
begin with. The only remaining offender is the legacyImageChanged()
method, imposed by the LegacyService interface.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'master' of https://github.com/imagej/imagej
Merge branch 'master' of https://github.com/imagej/imagej
Clean up after LegacyServiceTest

It was exactly the type of side effect this developer had to debug
earlier, for a non-trivial square hours. This test used to pass on Linux
only for some obscure reason that resulted in a different unit test
order.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Verify that the LegacyService was disposed after testing it

Just in case this breaks again, we want a *real* fast way to detect that
situation real quickly.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'windows-legacy-fixes'

Another fix triggered by jolly Jolanda Jenkins.

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