* improve AssetManager implementation
Notable changes are:
* removed the individual managers inside of d2asset, only one asset manager
* AssetManager now has caches for the types of files it loads
* created a type for TextDictionary (the txt file structs)
* fixed a file path bug in d2loader Source
* fixed a asset stream bug in d2loader Asset
* d2loader.Loader now needs a d2config.Config on creation (for resolving locale files)
* updated the mpq file in d2asset test data, added test case for "sub-directory"
* added a Data method to d2asset.Asset. The data is cached on first full read.
* renamed ArchiveDataStream to DataStream in d2interface
* moved palette utility func out of d2asset and into d2util
* bugfix for MacOS mpq loader issue
* lint fixes, added data caching to filesystem asset
* adding comment for mpq asset close
* Decouple d2asset from d2render
Notable changes in d2common:
* d2dcc.Load now fully decodes the dcc and stores the directions/frames in the dcc struct
* un-exported dcc.decodeDirection, it is only used in d2dcc
* removed font interface from d2interface, we only have one font implementation
* added `Renderer` method to d2interface.Surface, animations use this to bind to a renderer and create surfaces as they need
* added `BindRenderer` method to animation interface
Notable changes in d2common/d2asset:
* **d2asset.NewAssetManager only needs to be passed a d2config.Config**, it is decoupled from d2render
* exported Animation
* Animation implementation binds to the renderer to create surfaces only on the first time it is rendered
* font, dcc, dc6 initialization logic moved out of asset_manager.go
* for dc6 and dcc animations, the process of decoding and creating render surfaces has been broken into different methods
* the d2asset.Font struct now stores font table data for initialization purposes
Notable changes in d2core/d2render:
* Surfaces store a renderer reference, this allows animations to bind to the renderer and create a surface just-in-time
**These last changes should have been a separate PR, sorry.**
Notable changes in d2core/d2ui:
* ui.NewSprite now handles creating an animation internally, only needs image and palette path as arguments
Notable Changes in d2game:
Because of the change in d2ui, all instances of this code pattern...
```golang
animation, err := screen.asset.LoadAnimation(imgPath, palettePath)
sprite, err := screen.ui.NewSprite(animation)
```
... becomes this ...
```golang
sprite, err := screen.ui.NewSprite(imgPath, palettePath)
```
* Add PushEffect, handle effects in renderer
* Set effects instead of blend
* Stop using PushCompositeMode, use PushEffect
* Remove remaining composite mode things
* moved filter constants back to d2enum
* moving key and mouse button enums into d2enum
* moving render type enum into d2enum
* moving input even priority enums into d2enum
* moving terminal enums into d2enum
* Fixes#496 using ebiten.SubImage to Render Section of a Surface.
I had to add matching functions to both animation and sprite to get it to be called
for a sprite object.
* Fixed linter warning on comments for Sprite and Animation.
* Removing what's remaining of the old Sprite re-generation and caching.
