Complete -w, --viewer argument properly
Add ImageMagick viewer example to config
Add changelog generation script, and makefile target
Revert "Add changelog generation script, and makefile target"

This reverts commit f18252bd54366e11df86a89d75a439dbcd4c88f9.

The change was made mostly to accommodate inclusion of a changelog in
the Arch distribution. It has been brought to my attention that said
changelog is intended to be about the changes to the packaging, not the
packaged software. Therefore this script is no longer needed.
Use <<< instead of echo
List config file paths if no viewer is configured
Add information about configuration settings to --help text
Add note about config files as attack vector
Don't wrap output except for the --help text
Prefix echo with @ in makefile
Bump version
Version 1.3.1

Changelog:
- Complete -w, --viewer argument properly
- Add ImageMagick viewer example to config
- List config file paths if no viewer is configured
- Add information about configuration settings to --help text
- Add note about config files as attack vector
- Don't wrap output except for the --help text

Signed-off-by: Emil Lundberg <lundberg.emil@gmail.com>