[JENKINS-13995] Disabled the automatic pop-up of context menu.

Instead, it shows a small 'v' icon to the right that needs to be clicked
to open a context menu.
[JENKINS-13995]

Fixed a bug where the context menu anchor 'v' disappears even when the mouse is still over a model link.
[JENKINS-13995]

Added logging more liberally, and fixed the problem.
The root cause was that when the mouse enters a hot spot, I wasn't cancelling the previous delayed hide timer.

This fix eliminates the need for the hack in the hide method where I was testing if the mouse was still over the hotspot.

Conflicts:
	changelog.html

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
[JENKINS-13995]

Now that the context menu is open only when clicking 'v', the tooltip on model link should
be displayed as soon as the mouse hovers over it.

Conflicts:
	core/src/main/resources/lib/layout/breadcrumbs.js

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
[JENKINS-13995]

Made the 'v' icon bigger to increase the hit test area, and improved the alignment
logic so that the text and the 'v' icon gets vertically aligned.

Conflicts:
	core/src/main/resources/lib/layout/breadcrumbs.css

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>