Install FTS into /opt instead of /root

[phreed]

Install FTS into /opt similarly to the previously documented location.

Create an /opt/fts-config directory with links (symbolic or hard?) into the installed configuration files.
This will be used to preserve compatibility even if locations (or names) change in the installed files .

Ideas:
Rather than /opt/fts-config use the previous install location /opt/FreeTAKServer for the config links.
The new install location will be /opt/fts.env.