Allow messages to have expressions resolved at code generation time

Allow messages in the @Message annotation to allow expressions in the format of:

${property.name:default}

A warning message should be generated if the property name was not found. If not default is found an error should be generated.

The properties file needs to have the same fully qualified path and name of the interface. The properties file will not be used at runtime. There should also be an annotation processing option to allow a path to a properties file.