Log Message:
Update to 0.22

Upstream changes:
0.22      2018-10-13 22:24:46 -0400
  - Production version identical to 0.21_01

0.21_01   2018-10-11 22:53:43 -0400
  - Documentation fixes
  - Handle DLLs with upper-case characters in extension on MSWin32 (gh#9)