Changes aren't detected on types implementing IList

Steps to reproduce:

1. Open `Document`, select `Element`, press `Add` next to `Obj`, and try changing both the `Data` fields.
2. Notice neither field is marked as being set.
3. Open the `Data` script and comment out `#define IMPLEMENT_ILIST`
4. Repeat step 1 and see that the changes cause the fields to be marked as set.

Actual results: 

Expected results: 

Reproducible with versions:  6000.f1

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): Windows

Notes:

•  When a change is made we do a comparison between the old value and new one, if nothing changes we ignore it. The check we do is a little complicated because of all the different data we may be comparing, in 1 part we do a check to see if the values are IList, if they are we then compare the contents of them to see if they match. So here they are both empty and considered a match and we assume nothing changed. We need to also consider the contents as well as the items.