Party mods with "redeclaration means addition"

[hazer-hazer]

Now, mods cannot be redeclared as they're just items as others (funcs, structs, etc.)
Anyway, sometimes it can be convenient to "add" something to existent mod.
I propose this syntax:

party mod a {
     func foo {}
}

party mod a {
     func bar {}
}

As a result, we got a one mod a which includes both func foo and func bar.
This is pretty much like what C++ does.