Fix #4486 (No JSLint icon tooltip in some states) & small cleanups

Fix bug #4486 (JSLint icon has no tooltip in some states) -- Don't use CSS to filter clicks on icon depending on state, since killing all mouse events also breaks tooltip. Use JS to filter instead.

Also clean up some comments in the JSLint plugin; remove confusing unused/unimplemented argument in StatusBar APIs; and tweak folder tree Refresh menu item for less ambiguity (ran by NJ earlier).