[Travis] Update scripts to install like documented

Install legacy via composer, use offical permissions* and
cleanup script for readability.

\* prefer acl since it will avoid issues for commands executed
   as something else then www-data.
EZP-22568: Add Apache configuration & use for travis tests

Aims to add offical Apache configuration which is reused for testing
infrastructure as well, so avoiding duplicating vhost config across
online documentation and test infrastructure.

This reverts commit 808d69908b4f9117851c2667e59ac296c4c7e52f.