Package 0.2.0

• Added functions pool_intadj.R, pool_performance.R, psfmi_mm.R, psfmi_mm_multiparm, psfmi_perform, psfmi_stab.
• Added the class statement smodsmi to the functions psfmi_lr, psfmi_coxr
  and psfmi_mm.
• Added the following output object information to psfmi_lr, psfmi_coxr
  and psfmi_mm: model_type, predictors_in, predictors_out, fit.formula, predictors_final and predictors_initial.
• Excluded function miperform_lr.
• Changed name object multiparm_p into multiparm.
• Updated vignettes.