resolved #4 | removed bar shadow from bar chart subviews
updated pod spec and read me
Merge branch 'master' of https://github.com/Jawbone/JBChartView

Conflicts:
	Classes/JBBarChartView.m

Also added doc comments to - (JBBarView *)barChartView:(JBBarChartView *)barChartView barViewForIndex:(NSInteger)index;