4.7.6

• Fixed an example in Bchronology that was adding titles/labels incorrectly
• Updated vignette to show how to customise plots
• Fixed a bug where an error for identical positions (with no thickness errors) was not being shown
• Fixed an issue with positionNormalise
• Fixed an issue with jitterPositions by replacing it with artificialThickness that enables customised amounts of jittering when there are identical positions and no thicknesses
• Forced ids argument in BchronCalibrate and Bchronology to be unique otherwise causes problems with plots