IDE: Turn a phrase positive in messages options. "Hide icons" -> "Show icons". Add hint.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@46736 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: Improve layout in Window options frame.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@46737 4005530d-fff6-0310-9dd1-cebe43e6787f