add support for testsuite parameter (#142)

[chbiel]

make it possible to spedify a testsuite within phpunit.xml with attributes and execute the specified 's in parallel

[julianseeger]

Nice, thanks for this.

I'm just wondering about files but not directories. Your patch supports suites with files but doesn't support directories, does it? (https://phpunit.de/manual/current/en/organizing-tests.html#organizing-tests.xml-configuration)
Actually, I haven't seen a testsuite with files in practice. Is it much harder to add directory support? If not, it would be nice if you could add it.

[chbiel]

No problem, I need this for a project with many legacy tests with messed up test structure ;)

I added directory support and (apparently) support for mixed file/directory suites.
I wasn't sure if I should make it complicated with another option to filter duplicates (when mixing files and directories) so I forced, that no duplicate tests are allowed when using --testsuite parameter.

It's important to mention, that the 's are not executed in order as mentioned in the phpunit docs. For paratests it is only to add specific files to a testsuite that will be also executed.

[julianseeger]

I wasn't sure if I should make it complicated with another option to filter duplicates (when mixing files and directories) so I forced, that no duplicate tests are allowed when using --testsuite parameter.

Sounds good. Getting an error is better than having duplicates because of a senseless config and not noticing it.

It's important to mention, that the 's are not executed in order as mentioned in the phpunit docs. For paratests it is only to add specific files to a testsuite that will be also executed.

The order is always mixed up when parallelizing the tests, so +1 for that.

Thanks again and this in going to be version 0.10.0