Made a computed convenience property (used for abstraction purposes) readonly.
merged primary master and resolved conflicts
Merge pull request #958 from GreatApe/gk-browser-navigation-workaround

Made a computed convenience property readonly
Add `+[RLMObject objectWithKey:]`

Fetches the object with the given primary key, or returns nil if it doesn't exist.
Fix typo
Rename to objectForPrimaryKey: