Fix bugs with Collection loaded status

- should not be loaded after #clear
- sould be loaded after #load
Merge pull request #31 from ryansouza/patch-2

Fix bugs with Collection loaded status
activerecord relation-ish collection

* simplify lazy loading
* Collection no longer a Array subclass
* blacklist in-place modifications
Bump to 0.5.1.pre1
fix collection equality

* awesome print formatter shows attributes and records
Bump to 0.5.1.pre2