new_comments.pl: use Tie::IxHash for non-random hash order

Otherwise t/new_comments.t may fail with perl 5.18.
Strassen::CNetFilePerl: reset hash iterator in convert_wegfuehrung

Otherwise there are warnings with perl 5.18 in the form of:

    Use of each() on hash after insertion without resetting hash iterator results in undefined behavior at .../StrassenNetz/CNetFilePerl.pm line 150.
first steps for travis testing

* don't prereq "difficult" modules like Image::Magick or X11::Protocol
* use "test-no-cgi" target
added .travis.yml
added Geo::Proj4 to list of uninstallable dependencies
travis build: removed 5.8 because of DBD::XBase issues
travis: added GD and dependencies to the list of uninstallable dependencies
travis: install deps via apt-get, call "make ext"
more system prereqs needed for Geo::Proj4 and DB_File under Ubuntu
.travis.yml: added agrep to list of pre-installed packages
.travis.yml: added reasons for installing packages
.travis.yml: installing GD should work now
travis testing: define BBBIKE_TEST_FOR_LIVE=1

So bbbikedraw.t won't try to test the ImageMagick backend.
.travis.yml: installing missing fonts