Reverted incorrectly modified code in 3b9bb51321.
The newly created node becomes a child of the parent parameter
and is deleted together when parsing ends.
If there is an empty (unused) <defs /> inside the svg file, this can cause problems.
<defs> node is managed separately in loader->def.
So it doesn't have to be added to loader's list.
vector is designed for c++ syntaxes,
it works properly when c++ memory allocator is applied,
Here svg_loader uses c style structures which allocated using malloc()/calloc().
That brings the memory broken of stl vectors.
So, we replaced it with our customized SvgVector to easily fix it.
remove unnecessary condition.
implementation won't be included multiple times not like headers.
Thus this condition is unnecessary.
Change-Id: Id37e675c40ce7213a06c950da8e5ca17ff7245c9
picture now affords the memory data as input source so that
user can pass svg data memory directly.
Change-Id: I246c09b682a2d60e53ad556ce0c90337142ee4f1
