'writeln' added
[log] IDEA-116242 Allow multiple users selection in the log filter

* Let FilterPopupComponent return several filters instead of one.
  Filter results will be united with OR.
  Clarify this fact in javadocs.

* UserFilterPopupComponent: open a multi-line editor popup to enter
  user names.
* Names can be separated with comma, | and \n.
* Since there can be several user names, persist not single users,
  but user groups. Use a custom class, because List<List<String>>
  seems to be not possible in PersistentStateComponent by default.
* Rename the State property to avoid conflicts when upgrading.
* Display user names like this: "John|Bob". If the name is too long,
  shorten with ellipsis; still display full names in tooltips.