Internal improvement of slot visualization
Fixed #1326 causing parts of candlesticks not to print from Chrome's printing dialog.
Fixed #3094 causing series Z index to change after Series.update.
Fixed #3098, plot area size of a pie chart not being recalculated after the legend size changed.
Added demo for Base64 marker symbols.
Fixed #3104, touch panning not being able to pan outside the data range even if the axis min and max options were outside the range.
Update read me
Update readme.md