edje: add svg support to parse and store a svg file as a vector object in .edj.

edje: add svg support to parse and store a svg file as a vector object in .edj.

Summary:
This is the svg loader which will parse the svg file and store it in a intermediate structure.
It provides the helper function to get EET descriptor to save the structure into eet file.

NOTE: Not all svg attributes are handled yet. but most common attributes are handled .

Reviewers: Hermet, cedric

Subscribers: Hermet, cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D3868

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>