Issue #1265434 Expose relation in an entity list wrapper containing all related entities by jsacksick.

Issue #1271046 by Damien Tournoud and jsacksick Expose the relation-type specific fields. (against my better judgement.

This reverts commit 9c46180a.

Conflicts:

	relation.module

Removing a function body that was duplicated from relation.module. Replaced with a wrapper function.

Finishing up the support for creating relations via entity api. Moving most of the code from relation.module into relation.rules.inc. Dropping a lot of old code that was just experimental