allow a string to be used in onGet for attributes

Currently `onGet` doesn't work when passed a string as a function because when 'getAttr' is called in `initializeAttributes`, just the attribute config hash is passed in, without the `view` member that is needed to find methods by name.
Add missing semicolon
add test for onGet by string in attributes
Merge pull request #236 from caleb/fix-attributes-onget

Fix attributes bindings with string `onGet` methods