Initial terrain domain work
Properly use map cordons in domain generation, fixing maps where landmasses are connected to the world edge.
Factor out the CVec direction list.
Comments, formatting, and a some code style conformance tweaks
Properly deal with FindUnitPathToRange

This fixes boats attacking land targets.
Replace DomainIndex implementation

Switch from Dictionary<CPos, int> to List<int>, improving both
performance and memory usage, recouping the losses in
66455c1013c1aba095eae217c06a3778135be898
Bounds tweaks and reorg

Don't allocate so much pointless memory in DomainIndex, and spin it off
into its own file.
Fix domain index bounds

Fixes movement issues and a crash.
Add self to AUTHORS
Minor style fix
Move BuildDomains from World into DomainIndex.  More refactoring to come later.
More style fixes
Properly use Drawing.Rectangle in domain calculation