fix bug with null passed as $doc

This fixes specific issue with findOne() returns null on empty collection
remove rogue print statement
add modomo configuration support
fix bug with findOne not doing findOne
add support for dynamic location of Collections and Models plus the class names

Use: (assuming MongoDB collection is "people")

    // For collecitons
    Modomo\Config::$collectionNS;                                   // \Collection\People.php
    Modomo\Config::$collectionNS = 'App\\Collection';               // \App\Collection\People.php
    Modomo\Config::$collectionClass = '{{mongo.coll}}Collection';   // \App\Collection\PeopleCollection.php

    // For documents
    Modomo\Config::$documentNS;                                     // \Document\People.php
    Modomo\Config::$documentNS = 'App\\Document';                   // \App\Document\People.php
    Modomo\Config::$documentClass = '{{mongo.coll}}Document';       // \App\Document\PeopleDocument.php