Commit 1.23

Multiple hero invasions appear to work. Own and destroy system also
works. Code needs LOTS of tidying and rewriting. Working on loading from
cache.
Revert "Commit 1.23"

This reverts commit 14ec0a2224960c94efc91710295074a8f7f027d3.
Commit 1.23.5

Repaired previous commit. Loading from cache. Multiple hero invasions
working. Improve script.