Minor release 0.7.8

Structura minor release

Changelog:

• fixed crash when shooting enemies

• move the attack timer to a better location on the screen

• shell gates text hover

• on game over only offer to quit , a new game can be chosen from the launcher

• stack transfer operation menu

• proper cleanup on enemy death

endgame work (work in progress):

• added mothership nodes, each shell gate has 3 , initially cloaked

• message from command when arriving on the last shell

• trigger to decloak all mothership nodes

• if all mothership nodes are destroyed, the mothership will be decloaked

• the mothership will be a boss fight (still to do)