fixed PY-13177 PyCharm hangs on adding incorrect interpreter (python3-pyinotify)

added timeout for process to destroy it if failed
invoke 'save' after 'mark root' action to update iml files immediately
test added
GWT builder: test added
Merge remote-tracking branch 'origin/master'
Unneeded exception dropped
EA-55292 (NPE fixed)
IDEA-121664 Search Everywhere: results from different categories appear mixed
provide remove assignment fix for silly assignment inspection (IDEA-125993)
junit: accept custom matcher descriptions (IDEA-125942)