* 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
* fixed lint errors in button.go
* fixed lint errors in checkbox.go
* Removed d2ui singleton, fixed nearly all lint errors
- Changed `UI` struct to `UIManager`, removed singleton
- UI element provider functions are now methods of the UI Manager
- Screens now use the UI manager to create UI elements
- game panels in d2player now use the UI Manager to create UI elements
- Only the UI manager knows about "widgets"; calls to `d2ui.AddWidget` in Screen instances have been removed
* changed ui element provider methods from `Create` to `New`
The split between d2ui and d2asset Font version caused incorrect caching between the two. After looking at d2interface.Font, I saw the d2asset was the most recent and more tightly and cleanly packaged.
I therefore removed the old d2ui.Font and embedded the d2asset version in the d2ui.Label and d2ui.Button.
Looking at the code of d2ui, it would be logical to completly swap it for their d2gui version. But at least for the moment, the d2ui.Button as more functionality since it embeds a Label (instead of a font), and this label now has multiline horizontal alignement.
* 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
