Update jqBarGraph.js

Added new valueStyle optional function param for complete control of how value is used as a label.
Removed trailing newline
valueStyle is checked to make sure it is a function before trying to call it.
Syntax correction (missing quotes supplied).
Syntax correction.
Merge pull request #8 from philcrow/master

Add valueStyle param, which if not null is a function called to format the value for display.