Initial stab at Rcpp for meiosis simulation
meiosis.cpp: fix small bug
function to print a vector
Add stuff for using Rcpp from package
Add files that Rcpp added
Merge branch 'master' into Rcpp
split out random_int to separate .cpp file
print_vector.cpp -> debug_util.cpp
Add Roxygen2 docs for sim_crossovers
BIG CHANGE: revised format of output of meiosis() and cross().
Add to ToDo list
meiosis.cpp -> sim_meiosis.cpp
Another format change: chromosomes as data frames not lists

 - syntax is the same and easier to look at
Makefile: constructing vignette

[skip ci]
Add tests of create_parent()
check_individual: some fixes; add tests
check_individual: another fix
R/sim_meiosis: add note about sim_crossovers function
tests of sim_crossovers, meiosis, and cross
Update ToDo

[skip ci]