Updating via the .deb file breaks install

[iskandervdh]

Updating Spinup via a .deb file wipes all the files in /usr/share/. This is expected behavior, so we should avoid storing files there.

Things to change:

• The Spinup binary should be placed in /usr/bin/ directly or symlinked to some place like /var/lib/ or /usr/lib/.
• System wide config should be stored in /etc/spinup/
  For nginx we should symlink the user's config files to /etc/spinup/nginx/<username>/ and change the nginx.conf include directive to include /etc/spinup/nginx/*/*.conf. For each new user that creates a project we need to symlink their ~/.config/spinup/nginx folder to /etc/spinup/nginx/<username>.