Currently the nginx reload cron fails on Debian 9 because the path to
systemctl is /bin/systemctl rather than /usr/bin/systemctl.

CentOS 7 places systemctl in both /bin and /usr/bin, so we can just use
/bin/systemctl as the full path.

Federation self-check respects matrix_synapse_federation_enabled

`matrix_nginx_proxy_data_path` has always served as a base path,
so we're renaming it to reflect that.

Along with this, we're also introducing a new "data path" variable
(`matrix_nginx_proxy_data_path`), which is really a data path this time.
It's used for storing additional, non-configuration, files related to
matrix-nginx-proxy.

Start appservice-irc as non-root

Add option to enable Dimension widgets serve sites with self signed certs

Fix Matrix homeserver name in Dimension configuration

It's been reported that YAML parsing errors
would occur on certain Ansible/Python combinations for some reason.

It appears that a bare `{{ matrix_dimension_admins }}` would sometimes
yield things like `[u'@user:domain.com', ..]` (note the `u` string prefix).

To prevent such problems, we now explicitly serialize with `|to_json`.

Fix Dimension documentation

Related to #107 and #111 (Github Pull Requests)

Provide Dimension documentation

Implement self-hosted Dimension server

Related to #108 (Github Pull Request).

Fix indenting of generators value

allow exposing mautrix_telegram port

Upgrade riot-web to v1.0.3

Add support for custom MXISD templates

Related to #105 (Github Pull Request).

Related to #105 (Github Pull Request).