Merge playbooks/Ansible rewrite

[Nakaner]

I wrote the playbooks at a time when I had fewer experience with Ansible than nowadays. The result was a collection of playbooks which left the most difficult parts (asynchronously running the OSM data import) out. This pull request merges the playbooks to one large playbook but gives users who prefer to reuse parts of the playbook the choice to pick out what they need. It also includes a couple of other cleanups:

• Building map styles is now handled by the playbook.
• Apache configuration makes use of the conf-available mechanism of Debian's Apache package (useful for LetsEncrypt).

[DerDakon]

I squashed some things together, especially I folded whitespace fixes back into the original commit.