Revert "Removed awkward BattleUnit copy constructor, which fixes a memory leak"

This reverts commit 9e4c26237bc14456f9e62d177eea5d503b89b57b.
Revert "Fixed indentation; broken by previous commit"

This reverts commit 30c97feeb251291d1f26ae992caf8ecb2a645a15.
Revert "Memory leak fixes"

This reverts commit 10a46ddf58f6e6425e8ad74590a6cf46b8254126.