Patch for Ice for C#, 3.0.0 and 3.0.1

[michi]

Attached is a patch that fixes a problem with class sequences that use the collection mapping. For example:

// Slice
class A;
sequence<A> ASeq;

interface foo
{
    ASeq op();
}

If the sequence contains a null element, the unmarshaling code raises an exception.

Note that this patch is nessary only if you use the collection mapping (not the array mapping) for sequences of classes, and only if the sequence contains null references.

The attached patch is relative to the 3.0.1 release. If you are still using 3.0.0, don't use this patch but, instead, copy the attached Patcher.cs.txt file into Patcher.cs in the source tree. (The attached Patcher.cs.txt works with both 3.0.0 and 3.0.1.)

Cheers,

Michi.