style fixes
Version incremented to 2.5.3.
Changelog extended
Syntax fixes for changelog
Merge pull request #1243 from dvvrd/robots

QReal:Robots 2.5.3
Some late syntax fixes for changelog
new SVG icons from Tatiana. Also, very old iconsets removed.
rearranged blocks on palette
fixed encoding in license file
rewritten code related to svg/png file selection and loading in sdfRenderer
- images renderer will not query file system at all if image is in cache
- moved image cache-related code to separate inner class
made vera++ happy
Merge pull request #1244 from qreal/icons

new SVG icons from Tatiana. Also, very old iconsets removed.
lost slash in editorPluginInterface
Merge pull request #1249 from efim/widgetWOEditor

Widget wo editor