ZF-2122: Enhanced Describe Table

Description

Enhance describeTable() method to report metadata about table relationships, then use this metadata to populate Zend_Db_Table referenceMap.

Comments

These metadata may be unavailable in some RDBMS brands, e.g. SQLite, MySQL MyISAM.

Please categorize/fix as needed.

This doesn't appear to have been fixed in 1.5.0. Please update if this is not correct.

Reassigning to Ralph since he's the new maintainer of Zend_Db