feat #1280: Selenium Java Robot layer

This commit contains a new implementation of the aria.jsunit.IRobot
interface to use the Selenium Java Robot.

The Selenium Java Robot tool is available here:
https://github.com/ariatemplates/selenium-java-robot

If the browser was launched with the Selenium Java Robot tool, it will
be detected automatically by the aria.jsunit.Robot class and the
corresponding implementation of the interface will be used.

close #1280
fix #1281 fixing random test failures with Slider and DoubleSlider

This commit makes aria.utils.dragdrop.Drag a static dependency of
the Slider and DoubleSlider widgets. It does not make sense to have
it as a dynamic dependency, as it is always needed, as soon as those
widgets are used. Moreover, using a dynamic dependency makes their test
fail randomly, as the dependency may not have been completely loaded
when the test starts, leading to errors.
fix #1282 fixing keystrokes-related failing tests on Mac OS

This commit fixes 2 failing tests on Mac OS, due to different keystrokes
on this operating system.
fix #  navigation keymap inconsistency

when an escape keystroke is registered before a dialog is opened, the navigation keymap contains 2 objects, and when the dialog is closed, the wrong one is removed.
This fix introduces a comparison between the "modal" property that is used in the dialog keymap configuration, so that the right object is deleted and the user defined one is still handled by its callback.

closes #