Type definitions for setters are missing return type

[guidoren]

Setters are emitted as:

set_example(value : Example);

If implicit allow any is enabled that will compile fine; otherwise it is a compile error. Instead, this should be emitted:

set_example(value : Example): void;

[andry-tino]

Will always emit the return type in order to fix this. \

Scope

This feature will only be available in the ScriptSharp definition generator as we want to introduce a flag in the normal transpiler for emitting void and any explicitely or not (same as implicit allow any)