Version 2.5-0

• New: Overlay now works for gg plots
• New: gg option for visreg2d
• New: Improved support for betareg models
• New: Support for polr models
• Changed: visreg2d now split into calculation and plotting functions
• Changed: vignette now HTML instead of PDF
• Fixed: Formula parser now handles nested parentheses
• Fixed: Multi-reponse models with missing residuals() methods
• Fixed: Rugs now work with gg plots
• Fixed: Formula parsing for strata() in coxph models