Update jsperf.com links in Performance page

[hkarakose]

There are new revisions of following performance tests in jsperf.com.

• KineticJS vs EaselJS Render
• fabricjs vs kineticjs/fabric

jsperf links located in https://github.com/ericdrowell/KineticJS/wiki/Performance should be updated.

kinetic.js perform faster in the more recent performance tests.