- keep vm class names in test discovery traces
- capture non default constructors

use MultiMap as return type of com.intellij.execution.testDiscovery.TestDiscoveryProducer.getDiscoveredTests

possible issue fixed: result is set after state, so, client from another thread can get null

Alter border for both main and arrow parts despite which one is hovered. Alter background for hovered part only.

IDEA-171412

Use parent node from next grouping policy in chain in that case

IDEA-186725

Currently it is unnecessary because there is no clear distinction between none and directory groupings as it was before when only 2 groupings were available

* do not suggest to move ranges to another changelist if tracker is not valid