* first version of svg support
* merge some nanosvg pr
* look for svg icons first
* bug fix
* scale svg depends on screen size
* use irrlicht headers to get screen size
* finish isALoadableFileFormat for svg
* delete dynamically allocated memory
* fix wrong delete
* only rescale icons, due to size settings in stkskin.xml depends on the size of the image file
* check svg in FileManager::getAsset
* fix large icon in list
