visible_requires_status for menu powers
Move the player's max level to a config file

Use `max_level=` in `engine/stats.txt`. The default is still 32.
Merge pull request #780 from dorkster/level_max

Move the player's max level to a config file
Merge remote-tracking branch 'upstream/master' into fp_movement

Conflicts:
	src/GameStatePlay.cpp
	src/LootManager.cpp
	src/Map.cpp
	src/PowerManager.cpp
	src/StatBlock.cpp
Fix single enemy positions and target_neighbor
Fix teleport destination positions
Fix loot drop positions
Fix calcDirection and missile power gfx
Make power radius a float
Revert "Fix teleport destination positions"

This reverts commit 99c6d25200d4a91e3a8f301724b98d06f8aa2549.
Fix map_to_screen, enemy group spawns, teleportation, and target_neighbor
Fix wall powers and clean up PowerManager
Merge pull request #8 from dorkster/fp_movement

More floating point movement bugfixes
Fix collision_to_map() not including 0.5 offset
Improve error message for PowerManager loading powers
Define maximum level by xp table size instead of parameter
Merge pull request #775 from dorkster/bugfixes

 Fix removing currency on death
Replace requires_not by requires_not_status to be more consistent in style

Closes #407
Merge pull request #782 from stefanbeller/improve_error_message

Improve error message for PowerManager loading powers
Merge pull request #783 from stefanbeller/maxlvl

Define maximum level by xp table size instead of parameter