ArchiSteamFarm V0.6

Full changelog: 0.5.0.0...0.6.0.0

This release is mostly focused on bugfixes and enhancements.

• Fixed many issues with commands freezing, tasks being stuck and other inter-process threading issues. Hopefully ASF will now remain responsive regardless of what is going on.
• Implemented a steam-request limiter, which would hopefully help to minimize a chance of getting temporarily banned or captcha-required logins when you have many bots. Bots will now start and login to steam with small 5 seconds breaks.
• ASF will now refuse to load invalid config XMLs rather than crashing whole process.
• Added more useful comments to example.xml, regarding e.g. escaping special characters in password field.
• !exit command now exits whole ASF process, including all bots.
• Added 3 new commands !start, !stop and !status. You can now start and stop instances based on their identifiers. If you have e.g. marc.xml and sora.xml, you can tell marc bot to e.g. !stop sora to (temporarily) turn off sora bot and release it's account. Similar, you can later !start sora to turn it back on.
• Many other smaller bugfixes, improvements and enhancements to make ASF work better.