[DEPRECATION WARNING]: evaluating 'environment_directories' as a bare
variable, this behaviour will go away and you might need to add |bool to
the expression in the future. Also see CONDITIONAL_BARE_VARS
configuration toggle. This feature will be removed in version 2.12.
Deprecation warnings can be disabled by setting
deprecation_warnings=False in ansible.cfg.
This adds a custom filter that can be used in playbooks
to convert relative file/dir paths wrt home dir and
tht_root to absolute paths.
Also changes relevant playbooks to use it.