Added rank explanation to world map.

Also changed normal mode to only have 1 - 3 stars.
Auto-save when player beats level and when player dies.

Show a auto-save message when this occurs.
Fixed bug where pausing and quitting right after beating the level breaks
game.
Disable continues in Hard Mode.
Fixed rank explanation now that continues aren't possible.
Updated colors for world 2 and 3. More saturation.

Reworked challenges (many of them not implemented)
Including Blitz challenges!

Also updated the colors of negligentia graphics and added timer icons.
Fix bug where the title screen bg sometimes wouldn't show up.
Fixed bug where enemies don't explode if there are no lives left.

Also implemented most of the new challenges!
Got the blitz quests working. Still need to calibrate some reasonable
times.
Some tweaks to gold scores in hive 1 levels to make it less tedious.

Also made some early levels in hive 1 ramp up faster.
Added tracking of 'best-time' to non-boss levels.

Also removed unneeded code in main_game_transition_state and
reward_game_state.
Added pulse when gateway opens.
Added new art for power-ups.

Tweaked first couple levels of hard mode to be harder. Need to make it
clear that shit is getting real.
Removed lives and sparks from Challenge Mode.

It's not good game design, and the blitz achievements will provide the
same challenge in a more meaningful way.
Improved a couple of the boxes in the opening tutorial.