Added function to calculate rate ratios and rate differences. Also fixed bug in which confidence intervals for risk ratios and risk differences did not calculate correctly.
Added example cohort data on ebola survival.
Simon added functions for calculating risk ratios, risk differences and MH risk ratios for stratified risks.
Based on feedback after CRAN release, including additional feedback from Rothman, the option set has been expanded on the function pvalueplot to make it easier to build publication quality plots.
First release. One function added.