Fix #421 (Infinity loop after forwarding message from channel)

Fix logger to properly output text that contains '%' symbols.

Remove error suppression.
Fixes #413

Request limiter - prevent hitting Telegram's API limits

# Conflicts:
#	src/Telegram.php

Debug command

Crontab-friendly script

Add extra tests for getCommandsPaths method.

Fix for channel_post and edit_channel_post commands

Fix for channels where chat_id can be a text (developers should use getChat() to get numeric value!)

Make logger more flexible

Make access to the database easier

Add 'username' field to 'chat' table