removed duplicated assertion, refs #653
Add to Criteria support for IN and NOT IN operators in JOIN conditions
e.g. JOIN x ON (x.id = y.x_id AND y.foo IN (42, 51))
Use Criterion always when possible
Using Criterion allows to bind values in statements.
You can't use Criterion only for strings because in this method
you can't distinguish if it is a table name or value provided by user.
Additional assertion to ensure binding params doesn't change actual result
Add test for ModelCriteria to prove it support IN operator in JOIN conditions
Merge pull request #659 from staabm/separate_test

removed duplicated assertion, refs #653
Merge pull request #637 from arvenil/in-operator-in-join-conditions

Bugfix for IN operator in JOIN conditions
only generate findOneBySlug if required
Merge pull request #663 from havvg/feature/sluggable-querymethods

only generate findOneBySlug if required
add an excluded_parent_behavior to concret_inheritance behavior
clean
Merge pull request #664 from mazenovi/master

add an excluded_parent_behavior to concret_inheritance behavior
Fixed #651. Stupid typo.
Added multiple scope support in Sortable behavior.
Merge pull request #666 from marcj/issue-651

Fixed #651. Stupid typo.
fix deleting related objects

An object that is related to another one where this relation is required is meant to be deleted by Propel to ensure its behavior upon deletion.
If the relation is not required, but the foreign key defines a CASCADE behavior on deletion, the object will also be deleted.
Merge pull request #656 from havvg/feature/delete-object

deleting objects
fixed transaction leak when exception different from PropelException is thrown
Merge pull request #616 from marcj/sortable-multi-scopes

Added multiple scope support in Sortable behavior.
Issue #677: Set back reference when calling add
Provided tests for testing if all references are set for crossreferences before saving