Rename altsvgrast.h to its original name nanosvg.h and use a new
GitHub fork of nanosvg to maintain FLTK specific patches.
https://github.com/fltk/nanosvg
The diff files (altsvgrast.diff and nanosvg.diff) are no longer necessary
and have been removed. For more information see README.bundled-libs.txt.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12646 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
