A bunch of optimizations, features, code cleanup etc.

Some code was streamlined/optimized. Large edits should be noticeably less intense on the server.

So there's a new section for optimizing undo/redo history in the config.yml.

History compression:
- Enabling history compression will slow down edits a bit but will drastically reduce memory usage.
- It's your choice if you want to sacrifice speed for decreased memory usage.

History save to disk:
- Enabling this will have all history stored to disk rather than in memory.
- This will also uncap the history, allowing for an unlimited number of undos.
- Obviously will be slower than doing everything in ram, but having all the history on disk will free up a lot of memory.

Remember, if you need to do a really large edit, you can always bypass the history by using `//fast`.