Move remapElement() to coords and add a first unit test

git-svn-id: http://svg-edit.googlecode.com/svn/trunk@2416 eee81c28-f429-11dd-99c0-75d572ba1ddd
Some more unit tests for coords

git-svn-id: http://svg-edit.googlecode.com/svn/trunk@2417 eee81c28-f429-11dd-99c0-75d572ba1ddd