[svn r231] Changed: warnings are no longer treated as an error. Added some comments and cleaned up CallExp::toElem a tiny bit. Fixed: struct literals always reported inplace assignment even if they allocated a temporary. Fixed: passing stuff to a D-style vararg which did inplace assignment was generated suboptimal code.

module bug6;
class wrong { }
void bark(ref wrong s) { s = new wrong; }
void foo(wrong tree) {
    auto old = tree;
    bark(tree);
    assert(old !is tree);
}
void main()
{
    auto w = new wrong;
    auto old = w;
    foo(w);
    assert(w is old);
}