Writes a constructor that takes an explicitly listed subset of a bean's properties
for its arguments, and sets these properties initial values appropriately.
By the time generate(...) is called, all extra interfaces and imports from all
GeneratorExtensions should be incorporated into the passed-in ClassInfo object.
Note: this class pays no attention to whether users have marked any property variables as transient.
In fact, it will work most efficiently if users mark ALL variables as transient...