The play_area and floor Rects of Arena class have been moved into the arena_nt of each arena within globals.py.  This was necessary since new arena added by Virginia has a raised floor, and the play_area has no background color fill.
Merge branch 'master' of https://github.com/mk13/cs113_game into mk13-master
Merge branch 'mk13-master'
Uncommented gp_input stuff in Input class - it shouldn't crash the game anymore even if there isn't a gamepad attached.
(1)-'Arena' class now handles arenas with and without background images appropriately.  (2)-'arena_nt' now takes values for 'left_wall_x', 'right_wall_x', and 'floor_y', 'Arena' class changed accordingly.  (3)-'out_of_arena_fix' now works according to 'play_area_rect' size instead of using hard-coded values.  (4)-Added debug method '_draw_play_area_debug_border' to draw rectangles outlining the play_area, walls, and floor rects.
(1)-Created a sprite for player 2 by simply changing red to blue since this >>> STILL HADN'T BEEN DONE (I'm looking at you, Peter) <<<.  (2)-'_setup_player_sprites' is now a subfunction of new '_setup_players' function and takes a spritesheet filename parameter; this avoids code duplication for the second player's sprite setup.  (3)-'_draw_players' now has a subfunction, '_draw_player', that takes a player parameter; this avoids code duplication for player 2.  (4)-'_draw_players_debug' now has a subfunction, '_draw_player_debug', that takes a few parameters; this avoids code duplication for player2.  (5)-Reordering of some methods within 'GameLoop.__init__'.  (6)-'Player' class now takes a sprite parameter.
Fixed bug with 'out_of_arena_fix' and teleport skill.
Converted 24 bit pngs to 8 bit pngs to get rid of libpng warning.
Spawn points for player 1 and player 2 are now set within arenas, i.e. within globals.py.  This makes it easier to change player spawn points for different arenas.  Modifications to Player, Monster, Arena, and GameLoop classes were made to make this happen.
Player eyeball for non-sprite debug version now made on the fly in '_draw_debug._draw_players_debug'.