new test script for mapserver_address.cgi

Tests written using Plack::Test. A small fix in the CGI was needed to
workaround the FindBin hack here.
fix CGI::param() calls in list context

Newer CGI (4.05 and newer) warn on possible problematic usage of CGI::param()
is list context. Explicitly use BBBikeCGI::Util::my_multi_param for legal
usages, and fix the other by adding scalar() or so.
mapserver_address.cgi: fix more CGI::param in list context problems
Merge branch 'cgi-multiparam'
mapserver_address.cgi: fixed file list for fulltext search

The old approach with a negative filter was too error-prone, e.g.
non-bbd files were in this list, causing strange bbd errors on
parsing.