Prevent view records from being instantiated

Active Record does a lot of interesting things when records are
instantiated. Also, view records are readonly, so we should never need
to instantiate them anyway. Active Record also loads database query
results through a backdoor of sorts, bypassing the .new method
altogether.

With all of these things in mind, calling `.new` is being deprecated. In
v1.0, calling `ViewRecord.new` will raise a not implemented error.
Bump version to 0.5.1