svg: reversed argument order in svg.element
svg: fixed proxy constructor

Previously we were assuming that the proxy object element would always have a
root. If the element is the root then this is not the case.
svg: fixed root constructor
svg: fixed group constructor
svg: fixed rect constructor
svg: fixed path constructor
svg: fixed definition constructor
svg: added classes property to svg.element
Merge branch 'staging'
svg: use builtin search
Merge branch 'staging'
svg: fixed <use> element creation bug
Merge branch 'staging'