Collection maps contents change detection

[Xymanek]

aa00343 introduced "collection maps" where 1-n packages get fully inlined into a single map. However, there is an issue with the change detection (whether the map needs to be recooked during non-first cooks) in the cooker:

• if a package is changed (e.g. a new object is added) then the cooker will correctly recook the map
• if the list of packages is changed (e.g. added or removed) then the cooker will not recook the map

The best approach would be probably to store the definition lists as they were used during the cook in the BuildCache and delete the [Map].upk from BuildCache when there is a change (forces a recook)

[Xymanek]

No longer relevant with the change to DLC cook (#46)

[Xymanek]

Again relevant as DLC cook was reverted (#53)

[Xymanek]

#70 re-introduced DLC cooking, so this is no longer relevant again