Add tests for our issue tickets open.

The strategy is simple, even if the bug sounds obvious and is really simple to fix, still you must add an 'issue' test.

They all reside in tests/issues.

Example with ticket 24 (https://github.com/stricaud/faup/issues/24)

1) We add the urls mentioned in the ticket in a file with the issue number, such as tests/issues/24
2) We add the options of the command line tool that use the library and show our bug (there should always be a cli option for things available from the library) in a file named with the ticket number + '.options', such as tests/issues/24.options containing '-f domain' since there is a bug on the domain for those urls
3) We add a reference file with the expected output, such as tests/issues/24.ref which is the output of calling faup + options + issue_id

Add the test to cmake and we are done.