6.0 Changes

- Merged melee and spell crit methods. No longer a distinction
according to beta notes.
- Sinister Strike is back to 50e. Datamining suggests rumors were wrong.
- normalize_ep_stat was dead code. Gets overridden to settings object
value later.
- Additional commenting.
- Shrunk damage formula methods significantly.
- Default EP is set to AP while I test that mechanics are done right
(example, making sure 1 agi adds 1.1025 AP).
- Fixed set_openers() not giving Sub the full delay before casting
Vanish again. ShD > Vanish.
- Almost all remaining leveling perks have been added. Missing 1-2
Assassination perks. Assuming multiplicative behaviour.
- Blade Flurry procs poisons now.