DDC-3005 Defer invoking of postLoad event to the end of hydration cycle.
This feature makes guarantee, that postLoad event fires after all associations are populated
DDC-3005 Defer invoking of postLoad event to the end of hydration cycle.
1. Refactor handling of hydration complete: delegate this task to special object
2. Write test case for situation, when inside postLoad listener other entity is loading.
3. Make test, written on second step, be able to pass :)
Merge branch 'DDC-3005' into strate-master