Useful For Forge's test mods mainly.
Standardized data gen cache file's folder separators.
Added ItemModelProvider to BlockStateProvider for cleaner datagen code.
Added .gitattributes to fix datagen json's line endings correct on windows.
instead. New Lifecycle Event for requesting data harvesting. Mods will
be constructed, the registry will fire, and then a new Data event will
fire. Submit new data tag files to the data gatherer if you wish.
The game will shutdown after this. No other mod elements will happen.
Signed-off-by: cpw <cpw+github@weeksfamily.ca>