Python-base-app

* Make test suite compile on MacOS

* Add Debian packages in `python_base_app/templates/debian_control.template.conf` to enable loading
of Python module `python-ldap`

* Move functionality from `UnixUserHandler` to `BaseUserHandler`

* Add new class `LdapUserHandler` for authorization and authentication with an LDAP server

* Exclude template Python files `.coveragerc`

* Repair call of `coverage`

* Add test cases for class `UnixUserHandler`

* Add test case for health API
* Add babel-login to requirements.txt (triggered by new test case)
* Add dependency on package `some_flask_helpers`
* Add helper function `get_dns_name_by_ip_address()`

* Add class `Pinger`
* Exclude `sudo` package when not needed

* Fix usage of local make and export JOBS for WAF framework (just in case)

* Use local `make` script to set option `-j` according to `MAX_CPUS`