Bugfixes & AI Improvements — Andalia Steam update #351192

This patch was intended to be a small round of bugfixes for things I have come across in my playtesting, but it turned out to be a bit more involving. Íncluded Bugfixes: The target marker for unit abilities has been a bit buggy recently, so it sometimes wouldn't turn green, even though the targeted location was just fine and you could press the left mouse button to let the unit perform its ability. Now it behaves as intended again. Sometimes, especially on large maps, AI players had difficulties to find a path to the player base they wanted to attack, so they staid passive in their base indefinitely, even though they had enough forces to launch an invasion. This has been fixed by overhauling the way AI players approach offensives. Instead of trying to reach the enemy base directly, the AI player attack group now approaches the enemy in etappes. After each etappe the group will ensure tha...