Convert the legacy integration tests to use the maven-failsafe-plugin

The maven-invoked-plugin is very powerful, too powerful in fact to
work efficiently with integration tests. For example, we cannot easily
run them in Eclipse, and we als cannot easily skip them with -DskipITs
(and imply that with -DskipTests) but have to jump through hoops.

Better to use the maven-failsafe-plugin which was designed for
integration tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Clarify deprecations in the FilesUploader class

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
UpdaterTestUtils: do not forget META-INF when writing a .jar file

When writing a new .jar file made up of one or more .class files, we should include the sezpoz stuff in META-INF/annotations/.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Use the maven-failsafe-plugin for the uploader integration test

... instead of the maven-invoker-plugin.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
No longer fake handling of the skipITs property

Now that we no longer use the maven-invoker-plugin to run our
integration tests, we no longer have to skip *all* invoker-plugin
invocations when the property 'skipITs' is set...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'it-tests-failsafe'

This branch converts our integration tests to use the
maven-failsafe-plugin instead of the maven-invoker-plugin.

There are a couple of advantages to that:

- the invoker plugin can do way too much, not only allowing, but
  encouraging bad practices

- the verify step in integration tests run via the invoker plugin
  is typically written in Beanshell which makes it very hard to
  debug

- the invoker plugin runs Beanshell scripts in yet another way
  so that it gets really challenging to override, say, the
  com.apple.UIElement property to avoid ugly Dock icons to appear
  all over the place

- running integration tests via the failsafe plugin is much faster
  because of the constraints it imposes on integration tests

This branch not only addresses http://trac.imagej.net/ticket/1962
but also concludes that the failsafe plugin is the superior way
to run integration tests.

Thanks go to Curtis Rueden for the suggestion!

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