Update parser.js

Add support to catch attributes from symbol nodes.
This is a quick hack.
To have full support symbol should managed as defs and then copied as g, without display attribute.
But before adding tons of code, let's just make it work.
Update .travis.yml
Update parser.js

This was missing.
Now if width and height get parse correctly.
They were even before but if it was  width 18pt ( so 18 * 1.33 pixels ) and wievbox was 18, before no scaling was calculated.
Merge pull request #1574 from asturur/tag-symbol

Tag symbol
Update canvas.class.js

Added lockScaleFlip variable to scale object method
Update object.class.js

added lockScalingFlip, if set to true you cannot flip by accident an objec while scaling it.
Update object.class.js

Just grammar
Build distribution
Update canvas.class.js
Update object.class.js
Update parser.js

Delete function from parser. moved in element parser.
Update elements_parser.js

Added mono-object resolveGradient function. to be called befor reviver function.
Merge pull request #1595 from asturur/Load-Gradient-before-reviver

Load gradient before reviver
Merge pull request #1584 from asturur/Lock-Scale-Flipping

Lock scale flipping
Build distribution
Merge pull request #4 from kangax/master

sync with head