IDEA-121956 Multiple Carets: Add support for skipping next selection
IDEA-122076, IDEA-122172 Multicaret actions in quick find mode
'unmark root' action: allow user to cancel exclusion if excluded folder is selected (IDEA-23537)
skip non-java files with given word in literal even before retrieving text / searching the word / finding element at tree (IDEA-126201)
as ignored file set can be quite large, use map without entries for smaller memory footprint (e.g. in snapshot for IDEA-126201 number of ignored files is 126K, size of entries's  memory  for this number of elements is 2.5M)