add support for Bit2c exchange
Correcting pull request according to code review of pull request.
Bit2c exchange no longer unsafe.
issue #89: merge PR for Bit2c exchange

Merge branch 'master' of https://github.com/erezwanderman/openclerk into erezwanderman-master

Conflicts:
	inc/config.php.sample
	inc/crypto.php
	inc/database.sql
issue #89: merge bit2c PR into latest trunk

Merge branch 'erezwanderman-master'

Conflicts:
	inc/crypto.php
	inc/database.sql