Updated proposed shell implementation for Map and MapFactory classes

Note that there are known problems with this, e.g. both "portals" and
"items" will have to be objects that contain more information than
simple points. For example, portals must indicate which map will be
traversed to, and items will need to indicate the item type... even
obstacles may need more information, if we want to be clever
dd
rr
check
Couple of cool enhancements!
random
Merge branch 'map-and-map-factory' of https://github.com/CompSci11-1/DOTA-3 into map-and-map-factory
er
Merge pull request #9 from CompSci11-1/map-and-map-factory

Updated proposed shell implementation for Map and MapFactory classes