MAINTENANCE: Automated closing of pull requests.

This commit exists to close the following pull requests on Github:

Closes #1696 (close requested by 'pwendell')
Closes #1384 (close requested by 'pwendell')
Closes #845 (close requested by 'pwendell')
Closes #81 (close requested by 'pwendell')
Closes #1528 (close requested by 'pwendell')
Closes #1018 (close requested by 'pwendell')