Add setSelect() and getSelect() to modify select fields

[alpha0010]

Fixes #51

[alpha0010]

Hmm... it looks like we found a bug in Sphinx. I will investigate.

[alpha0010]

Reported: http://sphinxsearch.com/bugs/view.php?id=2519

[oohnoitz]

once its fixed in sphinx, i'll get this merged in.

[alpha0010]

It appears the problem is our HAVING test (which is unrelated to this pull). Technically that specific query can be rewritten as:

$result = SphinxQL::create(self::$conn)->select(SphinxQL::expr('count(*) as cnt'))
    ->from('rt')
    ->where('gid', 304)
    ->groupBy('gid')
    ->execute();

Maybe the Sphinx team decided HAVING should only be used in cases that WHERE is not applicable (for example, COUNT(*) > 123). I suppose we will have to wait for their developers to say if this is intended behaviour.

[oohnoitz]

it does seem like it's a regression since the test hadn't failed on the beta release on previous build versions.

although rewriting the query to the one you've provided would cause the test to pass, it would defeat the purpose of having the test in the first place, since we are checking to make sure that the HAVING query built is working and valid. but as you've stated, we'll just need to wait hear from the team themselves.

[oohnoitz]

HAVING tests will be updated in the #107 PR once tests pass.