added some kind of reference system (see list.h) to ensure particles/projectiles/enemies storing pointers to each other that they will not access a borked address.
To create a slave, pass ENEMY_IMMUNE for hp in create_enemy(). tip: create_enemyg(...) is an abbreviation for create_enemy(&global.enemies, ...).
There is something like a super fancy event system for Enemies' logic rules now: logic_rule will be called with t = negative special values like EVENT_BIRTH or EVENT_DEATH on corresponding events. cool, isn't it? well those values have to be filtered out (like if(t < 0) return;) if you don't use them so they don't do strange things with your locus.
Another Sarrg commit implementing score, different items and alternative player shot modes. Some things need improvements, some don't. But this commit fixes a bug with bomb counting, which is I think enough reason to push it now.
