Modified error handling to use implicit error catching to avoid fatal errors.

Source/Download.swift

@@ -156,8 +156,8 @@ extension Request {
                 do {
                     let destination = downloadTaskDidFinishDownloadingToURL!(session, downloadTask, location)
                     try NSFileManager.defaultManager().moveItemAtURL(location, toURL: destination)
-                } catch let moveError as NSError {
-                    self.error = moveError
+                } catch {
+                    self.error = error as NSError
                 }
             }
         }

Source/ParameterEncoding.swift

@@ -79,7 +79,7 @@ public enum ParameterEncoding {
         }
 
         var mutableURLRequest: NSMutableURLRequest! = URLRequest.URLRequest.mutableCopy() as! NSMutableURLRequest
-        var error: NSError? = nil
+        var encodingError: NSError? = nil
 
         switch self {
         case .URL:
@@ -121,22 +121,22 @@ public enum ParameterEncoding {
                 let data = try NSJSONSerialization.dataWithJSONObject(parameters!, options: options)
                 mutableURLRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")
                 mutableURLRequest.HTTPBody = data
-            } catch let serializationError as NSError {
-                error = serializationError
+            } catch {
+                encodingError = error as NSError
             }
         case .PropertyList(let (format, options)):
             do {
                 let data = try NSPropertyListSerialization.dataWithPropertyList(parameters!, format: format, options: options)
                 mutableURLRequest.setValue("application/x-plist", forHTTPHeaderField: "Content-Type")
                 mutableURLRequest.HTTPBody = data
-            } catch let serializationError as NSError {
-                error = serializationError
+            } catch {
+                encodingError = error as NSError
             }
         case .Custom(let closure):
             return closure(mutableURLRequest, parameters)
         }
 
-        return (mutableURLRequest, error)
+        return (mutableURLRequest, encodingError)
     }
 
     func queryComponents(key: String, _ value: AnyObject) -> [(String, String)] {

Source/ResponseSerialization.swift

@@ -81,16 +81,13 @@ extension Request {
                 return (nil, nil)
             }
 
-            let JSON: AnyObject?
+            var JSON: AnyObject?
             var serializationError: NSError?
 
             do {
                 JSON = try NSJSONSerialization.JSONObjectWithData(data!, options: options)
-            } catch let error as NSError {
-                serializationError = error
-                JSON = nil
             } catch {
-                fatalError("JSON serialization failed and did not return an error")
+                serializationError = error as NSError
             }
 
             return (JSON, serializationError)
@@ -128,16 +125,13 @@ extension Request {
                 return (nil, nil)
             }
 
-            let plist: AnyObject?
+            var plist: AnyObject?
             var propertyListSerializationError: NSError?
 
             do {
                 plist = try NSPropertyListSerialization.propertyListWithData(data!, options: options, format: nil)
-            } catch let error as NSError {
-                propertyListSerializationError = error
-                plist = nil
             } catch {
-                fatalError("Property list serialization failed and did not return an error")
+                propertyListSerializationError = error as NSError
             }
 
             return (plist, propertyListSerializationError)