Reworked ORM::Filter:

- Ability to join same tables (models)
- Ability to join tables with random specified attributes.

Example:

M1 -> filter( field1 => M2 -> filter( ...,
                                      _return => 'corresponding_to_field1_above' ) )

Simpler if M1 and M2 have declared FK between:

M1 -> filter( M2 -> filter( ... ) )

Join a table on itself (syntax example mainly):

M1 -> f( rgroup  => 551,
	 # ... more clauses,
	 f01 => M1 -> f( rgroup => 522,
			 # ... all what can be filter criteria,
		         _return => 'f02' ) )

Does it work?