• Rename some C source files & update doxygen documentation.
• Simplify some methods and the class structure.
• Clean up code and simplify wrapper functions.
• Documentation updates.
• Deal with factors containing only one level.
• Do not compute design matrices in ModelEnvFormula.
• Expand case weights if distribution = approximate().
• Assign names to user-specified transformation in case they are missing.
• The distribution argument may now be a function with one argument allowing for user-specified distributions.
• surv_test() ignored the alternative argument.