:sig
String expand_path(String path, String relative_to_path = "")

:params
path : path to expand
relative_to_path : base directory a relative `path` is resolved against
return value : the expanded path

:content
Expands a path: a relative `path` is resolved against `relative_to_path` (or the current unit's directory when that is empty), producing a normalized path you can hand to the file APIs.

:example
print(expand_path("sub/page.uce", "/var/www/site"), "\n");

:see
>sys
path_join
path_real
