Revert "PBKDF2 => scrypt; fixed postbit bug"

This reverts commit 89e4f78f1520a87753061fc50a3e637ac870400a.

Conflicts:
	flaskbb/user/models.py
Merge branch 'master' of https://github.com/sh4nks/flaskbb
Do not show "PM" link on posts by the current_user, as you can't PM yourself anyhow
Merge remote-tracking branch 'origin/master'

Conflicts:
	requirements.txt