* d2game/d2player/inventory.go: magic number lint cleanup
* d2game/d2player/mini_panel.go: magic number lint cleanup
* d2game/d2player/skill_select_panel.go: lint cleanup
* d2game/d2player/skilltree.go: removed all lint errors
* removed the rest of the magic number errors from d2game
* hotfix for bug i added in map engine test
* all magic numbers removed (excluding mapgen)
* move music path enumerations into d2resource
* move text dictionary (.tbl) loader into d2fileformats sub-package d2tbl
* lint fix, add doc file for d2tbl
* moved data_dictionary.go into d2fileformats sub-package d2txt, added doc file
* added sub-packages d2geom for geometry-related things, and d2path for path-related things
* moved calcstring.go to d2calculation
* move bitmuncher, bitstream, stream reader/writer from d2common into sub-package d2datautils
* fix lint errors in d2datadict loaders (caused by moving stuf around in d2common)
* move size.go into d2geom
* move d2common/cache.go into sub-package d2common/d2cache
* renamed d2debugutil to d2util, moved utility functions from d2common into d2util
* smooth camera with vectors
* add smooth cam support to map engine test
smooth cam now works in map engine test.
clicking or holding the left-mouse button will move the camera.
also works with freecam mode in single-player.
* Update ebiten_renderer.go
did not mean to edit this file
* Comments and newlines in engine.go
* Comments and newlines in object.go
* Comments and newlines in animated_entity.go
* Comments and newlines in missile.go
* Comments and newlines in npc.go
* Comments and newlines in player.go
* Removed object.go (incorrectly merged it in during rebase).
* Comments and newlines in renderer.go.
* Comments and newlines in map_entity.go.
* Comments and newlines in walk_mesh.go.
* Comments and newlines in viewport.go and tile_cache.go.
* Comments and newlines in stamp.go and wilderness_tile_types.go.
* Comments and newlines in everything else.
