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 #1274 Select widget with 'options' and 'value' binded.

If the options list changed, the value is no longer considered and
the first one is always selected