javascript loop optimizations when processing series/data

- Move some graph related function as part of MetrilyxGraph object to enable the possibility of using this.
- Change for ... in on array to simple for for better performance. (http://jsperf.com/for-in-vs-for-loop-on-array)
- Added false to addPoint and setData functions calls to prevent useless graph redraw ... we call an explicit redraw later.
- Some JavaScript syntax correction.