DGEngine v0.2.2

Release for Windows

now requires a C++17 compiler.

- add action to force screen draw
- add defaultTile when loading map
- add endianness library
- add gsl
- add initial save code
- add new CEL/CL2 file decoding
- add out of bounds tile to map
- add palette shift functions
- implement color cycling
- mind endianness in PCX decoder
- refactor Dun/Min/Til to mind endianness
- refactor LevelMap
- update save code

- update gamefiles
- add F1-F8 keyboard actions to add/remove gold, life, mana, experience (for testing purposes)

Note: This is a work in progress. Some things aren't perfect and that's known.
Delete previous saves to avoid error caused by changes.