Add geo api to cvmfs-server

This request adds the geo api.  It doesn't yet include any documentation, and I haven't written automated tests.  I have tested the rpm creation, and guessed at the debian configuration changes but didn't test them because I haven't yet learned to build debian packages.   Below are the configuration additions needed in a /etc/httpd/conf.d configuration file.  It also requires the mod_wsgi package for this to work.  I'm not entirely sure where to document that yet beyond the tech report.  Perhaps it could go in the apache config created by cvmfs_server snapshot, but probably commented out because not everybody will use it.

```
RewriteEngine on

# Change api calls to /cvmfs-api internally where it can be easily
#   caught by the WSGIScriptAlias below
RewriteRule ^/cvmfs/([^/]+)/api/(.*)$ /cvmfs-api/$1/$2 [PT]

# Enable the api functions
LoadModule wsgi_module modules/mod_wsgi.so
WSGIDaemonProcess cvmfs-api processes=2 display-name=%{GROUP} \
        python-path=/usr/share/cvmfs-server/webapi
WSGIProcessGroup cvmfs-api
WSGISocketPrefix /var/run/wsgi
WSGIScriptAlias /cvmfs-api /var/www/wsgi-scripts/cvmfs-api.wsgi

<Directory /usr/www/wsgi-scripts>
    Order allow,deny
    Allow from all
</Directory>
```

Mhh, I would not depend on inherited state but hand these variables in explicitly... If it is only used in `update_geoip()` please call it `_check_old_dbfile()` to emphasise its 'private nature'.