LCL: Improve PNG image support in TImage. Issue #20361, patch from José Mejuto

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41020 4005530d-fff6-0310-9dd1-cebe43e6787f
PNG test: add a groupbox for radiobuttons (did not work with QT). Improve anchors.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41021 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: Fix compilation with FPC trunk. Issue #24377, patch from Mario Ray Mahardhika

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@41022 4005530d-fff6-0310-9dd1-cebe43e6787f