Timestamp and user key options. Installation instructions.
Consistent ordering of options.
Edit README.md
Variable case & new line.
Variable capitalization.
Add line continuation backslash.
Removing USER optional field
Adding quotes around eval. -F user, token case change.

The quotes around the eval work for me now.
Updated README.md. Groups, install formatting

May want to `touch ${HOME}/.config/pushover.conf` in install commands?
Merge pull request #5 from adamlazz/master

Timestamp and user key options.