Adds customizable user script and user stylesheet.

App/Settings/Settings.swift

@@ -28,6 +28,8 @@ public struct SettingProperty<T: RawRepresentable>
     }
 }
 
+// - These coercions into RawRepresentable are stupid. How do I write specializations for each type instead? 
+
 extension Dictionary: RawRepresentable where Key == String, Value == String {
     public typealias RawValue = [String: String]
     
@@ -41,6 +43,18 @@ extension Dictionary: RawRepresentable where Key == String, Value == String {
     }
 }
 
+extension String: RawRepresentable {
+    public typealias RawValue = String
+    
+    public init?(rawValue: String) {
+        self.init(rawValue)
+    }
+    
+    public var rawValue: String {
+        return self
+    }
+}
+
 class Settings
 {
     static let shared = Settings()
@@ -80,4 +94,10 @@ class Settings
         
         return nil
     }
+    
+    @SettingProperty(key: "userScript")
+    public var userScript: String = ""
+    
+    @SettingProperty(key: "userStylesheet")
+    public var userStylesheet: String = ""
 }