0.4.5 Fix small bug in computing p-value for bn.test
      (unmodified).  Add test for bn.test (modified).
1.0 Huge release.  Add lots of methods (dc.test, fast.test,
      (mlink.test, rflex.test, etc.)  Dramatic restructure
      of many functions.
1.1 Add cepp.test (and related).  Fix some documentation.
1.2 Update *.test functions to return 'smerc_cluster' class
    instead of 'scan' class. Create print, plot, and summary
    functions for smerc_cluster class. Add ex argument to
    bn.test. Improve speed of flex.zones function.
1.3 Create flex_zones and flex_test to use C++ code for speed.
    Add vignette regarding how to use package.
1.3.1 Fix noLD testing bug.
1.4 Add optimal_ubpop for choosing a population upper bound.
