IDEA-16393 diff: prefer diff walker action in case of keymap conflict

allow to use same shortcut, as Next/Previous method
diff: disable LST rollback action in diff editor

Gutter marks are hidden for such editors
GWT ui.xml: support attributes for setters with more than one parameter and arbitrary types (IDEA-130149)
IDEA-89317 "Side Effects Found" dialog is ugly
CreateFromTemplateDialog: log.info exceptions to make it easier to trace creation issues
decompiler: for now disabled line numbers in inner classes