Redo/cleanup source code, upgrade discord.js

[filipnyquist]

Discord.js now recommends using discord.js-commando for modules/plugins:

• We should integrate it asap, move over the plugins to the new format introduced with commando.
• Better code quality checking/linting needs to be added so we keep the same format for all plugins.

[filipnyquist]

Most of the code is done and in the wunderbot-v2 branch, it is not ready for production yet as it´s missing:

• A working webinterface to change important settings
• The claimbot implented with chainquery instead of lbrycrd and the decoder.
• Documentation and README

These will be split up into different issues and added to the next sprint.