Beatmap submission system

[Lekuruu]

• [x] /osu-osz2-bmsubmit-getid.php
  • [x] New uploads
  • [x] Beatmap updates
• [x] /osu-osz2-bmsubmit-upload.php
  • [x] Decrypt osz2 package
  • [x] Update beatmap metadata
  • [x] Update beatmap thumbnail
  • [x] Update beatmap audio
  • [x] Update beatmap files
  • [x] Update osz package
• [x] /osu-osz2-bmsubmit-post.php
  • [x] Create new forum posts
  • [x] Edit forum posts
  • [x] Notifications/Subscriptions
• [x] /osu-get-beatmap-topic.php

[Lekuruu]

We are done! :tada: