The following command was used to determine the author of active contributions
at the time of source change:

    git ls-tree --name-only -r a5c80edd | grep -E '\.py$' | xargs -n1 git blame --line-porcelain | grep "^author " | sort | uniq -c | sort -nr

Its output is:

5707 author Bryce Boe
 284 author Ethan Dalool
  16 author Andreas Damgaard Pedersen
   9 author xoru

Both Ethan and xoru acknowledged via email the change from the GNU license to
the BSD license. Andreas was not asked due to the 16 lines being of no
consequence to the use of PRAW.