Finally fix the `install_server.sh` script.

Includes changes from a dozen bug reports and pull requests.
Was tested on Ubuntu, Debian and CentOS.
Fixed a few typos.
Merge pull request #1609 from badboy/install_server-fix

Finally fix the `install_server.sh` script.
Merge pull request #1627 from badboy/lru-fix

Fixed a few typos.