Alleged Domain Driven Design / Dependency Injection and other things

[rmil]

This branch was mostly focused on refactoring the code-base and taking advantage of dependency injection to decouple the packages from each other and made it more modular and hopefully easier to test. However, more refactoring will need to be done since I'm not satisfied with how the service packages are laid out and want to standardise on a certain style and also decide on passing by value / pointer. Hopefully I'll be able to resolve them later.

So this branch includes:

• Refactoring
  • Removed all global variables, introducing interfaces which will hopefully make it easier to develop for. Refactor infrastructure layer #3
  • Removed the logging package from all service/handler packages and improved greatly error handling Better logging #4
  • Find by path now separated from creator package for public usage
• Features
  • Quotes get/new/update
  • New sign-up sheets
  • Playlist update including playlist video items
• Fixes
  • Lack of arrival time for sign-up sheets
  • Incorrect errors being returned