Ported coffee charts to js

Signed-off-by: Sheik Hassan <solergiga@yahoo.com>

Tested
@naegelyd I removed `initialize` from core. B/c it's not being called, the height/width of the chart is messed up. Placing the code inside the constructor solves this issue.
Move y declaration just above the `if (yField) {` line so it is declared near its usage