Support string literals in type definition

[gr0uch]

Currently the record type definition only allows built-in constructor functions:

{ name: String }

This makes the record type definitions non-serializable. It should accept the name of constructor functions as well, and consider it as a special case:

{ name: 'String' }

This would also mean that these would be unacceptable names for record types. There are already unacceptable names (anything in Object.prototype) so this shouldn't be much of a problem.

[gr0uch]

Done d14401b