User-friendly general package providing standard methods for
meta-analysis and supporting Schwarzer, Carpenter, and Rucker,
"Meta-Analysis with R" (2015):
- common effect and random effects meta-analysis
- forest, funnel, Galbraith/radial, L'Abbe, Baujat and bubble plots
- three-level meta-analysis model and generalised linear mixed model
- Hartung-Knapp and Kenward-Roger methods for random effects models
- prediction intervals, tests for funnel plot asymmetry and the
  trim-and-fill method to evaluate bias
- meta-regression, cumulative and leave-one-out meta-analysis
- import of data from RevMan 5
