criteria: fix issue #2157 and added tests

[maxgalbu]

See the discussion here:
http://forum.phalconphp.com/discussion/1479/multiple-joins-in-oo-notation-fail

From what I saw, the problem was that the current_joins was merged with the join array instead of appended, so it resulted in something like this:

array(
    //first join
    0 => array(
        'type' => "LEFT",
        'conditions' => "...",
    ),

    //all the following joins
    'type' => "LEFT",
    'conditions' => "...",
)

instead of

array(
    //first join
    0 => array(
        'type' => "LEFT",
        'conditions' => "...",
    ),

    //all the following joins
    1 => array(
        'type' => "LEFT",
        'conditions' => "...",
    ),
)

I don't know how to copy a zval and I'm guessing I couldn't edit current_joins directly, so to avoid editing too much code I simpy added an array of array that can be merged with current_joins or copy-written on merged_joins.

[maxgalbu]

@niden do i need to resubmit this or can you reopen it?

[niden]

I reopened it but I don't think it will work since the old 1.3.2 branch had a different hash.

@maxgalbu if you don't mind just re-tracking 1.3.2 on your local and then submitting it, it would be great!

Thanks!

[maxgalbu]

done :)