Build EntityFieldQuery Wrapper System

Committed build of the query wrapper system supporting querying by entity type. Enable the new Wrappers Delight Query submodule to use it. I still need to add the code to generate bundle-specific query wrappers. The entity query wrappers can be used like this:

<?php
$results = WdNodeWrapperQuery::find()
            ->byAuthor(1)
            ->execute();

$user_node_links = array();
foreach ($results as $record) {
  $user_node_links[] = l($record->getTitle(), 'node/' . $record->getNid());
}
?>

The query wrapper supports chaining and overriding the operator, so you can also do something like this:

<?php
$results = WdNodeWrapperQuery::find()
            ->byAuthor(1)
            ->byTitle('%Test%', 'LIKE')
            ->execute();
?>

It supports order and range modifiers. I still need to add property and field specific orderby methods, but you can call the generic ones at this point:

<?php
$results = WdNodeWrapperQuery::find()
            ->byAuthor(1)
            ->orderByProperty('title', 'DESC')
            ->range(0, 10)
            ->execute();
?>

It supports fields and their value columns using dot syntax:

<?php
$results = WdCommerceLineItemWrapperQuery::find()
            ->byUnitPrice(10000, 'USD', '>')
            ->orderByField('commerce_unit_price.amount', 'DESC')
            ->execute();
?>

Wrappers Delight Query module now supports bundle-specific queries with fields. So, you can now do something like:

<?php
$results = ArticleNodeWrapperQuery::find()
  ->bySomeCustomField($value)
  ->byAnotherCustomField($value2)
  ->execute();
?>

Results will be of type ArticleNodeWrapper in this case. So, something like this should work:

<?php
foreach ($results as $record) {
  $output .= $record->getTitle();
  $output .= $record->getImageHtml('medium');
}
?>

Still need some code cleanup and tests.

Query system is built. When the Wrappers Delight Query module is enabled, the drush wrap command will generate both an entity wrapper and a query wrapper class for each bundle. The query wrappers work as described above, with the addition that they now support orderBy() methods. So, something like this should work:

<?php
$results = ArticleNodeWrapperQuery::find()
            ->byAuthor(1)
            ->orderByCreatedTime('DESC')
            ->range(0, 10)
            ->execute();
?>

It supports fields and their value columns using dot syntax:

<?php
$results = WdCommerceLineItemWrapperQuery::find()
            ->byUnitPrice(10000, 'USD', '>')
            ->orderByField('commerce_unit_price.amount', 'DESC')
            ->execute();

?>

The drush command will also generate custom orderByXXXXX() methods for every field in your entity bundle. It works with field types that have a "value" column, file types ("fid"), and entityreferences ("target_id"). Everything else will likely need some hand tuning.

I've added an addTag() method to the WdWrapperQuery class that will pass a tag down to the query inside.