Due to Issue #170, I've added some logic that'll change the systemd service that gets setup to call the 'amonagent32' binary rather than 'amonagent' for "i686" architectures. Not entirely pretty, but, it's better than failing as it does now.

"The binary for the agent is located in /usr/local/bin/amonagent", was not true for me when I installed. In my case it went to /usr/bin/amonagent.

Added installer check for debian that will lead to the unsupported message if on an architecture for which there isn't a suitable amonagent binary. I'm doing this because the installer ran fine on my armv7l machine, but the amonagent binary will not execute on it, nor would amonagent32 (obviously).

Adjusted string comparison expressions to be more robust (if [ $DISTRO == "astring"] is not as good as if [ "$DISTRO" == "astring"] because when DISTRO is undefined, bash will crap its pants.

Decided the string comparisons ought to all use double-quotes.