Adding support for non-file SVGs
Adding support for non-file SVGs

source.setter now uses Svg.set_tree() to set the tree and execute .reload()
Svg() can now reloaded/initiated using set_tree(tree) when source is not a file.
Svg() Constructor therefore does not require source parameter - which now defaults to None.
source.setter is only executed during __init__ when parameter is given.
rnixx/kivy,rnixx/kivy,inclement/kivy,matham/kivy,akshayaurora/kivy,inclement/kivy,rnixx/kivy,kivy/kivy,matham/kivy,akshayaurora/kivy,inclement/kivy,kivy/kivy,matham/kivy,kivy/kivy,matham/kivy,akshayaurora/kivy