Split main

Split up trout cod and open sim analysis into separate files as they
were getting too big.
se

actually calculating s.e., not s.d., because we are applying confidence
intervals to the mean.
bugfix

plot directory file paths
Chao unbiased estimator

Added option to select biased/unbiased chao estimator. unbiased is
default.
Plot of Chao estimates for secondary intervals.

window size of 10 for TC data