The return is a table with the following keys:
* main The normal location of component files. For a back-end Joomla!
component this is the administrator/components/com_example
directory.
* alt The alternate location of component files. For a back-end
Joomla! component this is the front-end directory, e.g.
components/com_example
* site The location of the component files serving the public part of
the application.
* admin The location of the component files serving the administrative
part of the application.
All paths MUST be absolute. All four paths MAY be the same if the
platform doesn't make a distinction between public and private parts,
or when the component does not provide both a public and private part.
All of the directories MUST be defined and non-empty.