Add uncommited generation checking to all the gen tasks.

If checking="true" on them, they generate their code to a String instead of a file, and compare that
against existing output.  If any generation would produce changes, the build is failed.

As a side effect, generation will now only write files if it's going to modify them, which should
eliminate some spurious compiling.



git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6349 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/cpp/presents/data/ClientObject.cpp

@@ -10,7 +10,6 @@ void ClientObject::readObject (ObjectInputStream& in)
     presents::dobj::DObject::readObject(in);
     username = boost::static_pointer_cast<util::Name>(in.readObject());
     receivers = boost::static_pointer_cast<presents::dobj::DSet>(in.readObject());
-    permPolicy = boost::static_pointer_cast<presents::data::PermissionPolicy>(in.readObject());
 }
 
 void ClientObject::writeObject (ObjectOutputStream& out) const
@@ -18,5 +17,4 @@ void ClientObject::writeObject (ObjectOutputStream& out) const
     presents::dobj::DObject::writeObject(out);
     out.writeObject(username);
     out.writeObject(receivers);
-    out.writeObject(permPolicy);
 }