- More code cleanup and codestyle updates

- Fixed some possible nullref exceptions
- Methods signatures now have up to 3 parameters before breakaing down each parameter in a separate line
- Method invocations have the same rule, except the first parameter will be in the same line as the invocation to prevent some ugliness when passing lambas as arguments
- Applied many more codestyles
- Extensions folder fully reformatted

src/NadekoBot/Common/Attributes/NadekoOptions.cs

@@ -6,7 +6,5 @@ public sealed class NadekoOptionsAttribute : Attribute
     public Type OptionType { get; set; }
 
     public NadekoOptionsAttribute(Type t)
-    {
-        this.OptionType = t;
-    }
+        => this.OptionType = t;
 }