-Fix: the AI speed control is done by the AI-core, individual AIs don't have to do it (so, AIs were delayed twice ;)
-Add: Support for AI-network-clients (an AI, connecting to a remote server)
-Fix: minor AI-core problems
-Indentation
-Whitespace
-DeMorgan's Law
-Test with NULL or 0 for non-booleans
-'\0' instead of 0 for chars
-Remove redundantly redundant comments (like DoFoo(); // Do foo)
-Join multiple short lines with a single statement
-Split single lines with multiple statements
-Avoid assignments in if
Simplify this check by testing the rail vehicle info flags instead of passing a global variable around.
Note: This is not exactly the original behaviour, because the Lev4 was always allowed to be built, but i guess that was a glitch.
