Make JSONDecodable handle String->Double conversion too

# Conflicts:
#	Sources/JSONDecodable.swift

Tests/JSONParserTests.swift

@@ -201,6 +201,7 @@ class JSONParserTests: XCTestCase {
             ("-123.45e-2", -123.45e-2),
             ("0.1e-1", 0.01),
             ("-0.1E-1", -0.01),
+            ("1472861857112", 1472861857112),
         ] {
             do {
                 let value = try JSONFromString(string).double()
@@ -288,10 +289,46 @@ class JSONParserTests: XCTestCase {
 
         // The Freddy parser behaves consistently across architectures.
         XCTAssertEqual(try? json.int("exceedsIntMax"), nil, "as int")
-        XCTAssertEqual(try? json.double("exceedsIntMax"), nil, "as double")
+        XCTAssertEqual(try? json.double("exceedsIntMax"), Double(anyValueExceedingIntMax), "as double")
         XCTAssertEqual(try? json.string("exceedsIntMax"), anyValueExceedingIntMax.description, "as string")
     }
 
+    // This test should also be run on the iPhone 5 simulator to check 32-bit support.
+    func testOverflowingInt32ResultsInIntWhenAppropriateWithFreddyParser() {
+        let anyValueExceedingInt32Max: Int64 = 4611686018427387901 // This is a 62-bit number that is not accurately representable as a double
+        let jsonString = "{\"exceedsInt32Max\": \(anyValueExceedingInt32Max)}"
+
+        let data = jsonString.dataUsingEncoding(NSUTF8StringEncoding)!
+        guard let json = try? JSON(data: data) else {
+            XCTFail("Failed to even parse JSON: \(jsonString)")
+            return
+        }
+
+        let expectedIntValue: Int64? = Int64(Int.max) > anyValueExceedingInt32Max ? anyValueExceedingInt32Max : nil
+        let actualIntValue: Int64?
+        do {
+            actualIntValue = try Int64(json.int("exceedsInt32Max"))
+        } catch {
+            actualIntValue = nil
+        }
+
+        // The Freddy parser behaves consistently across architectures.
+        XCTAssertEqual(actualIntValue, expectedIntValue, "as int")
+        XCTAssertEqual(try? json.double("exceedsInt32Max"), Double(anyValueExceedingInt32Max), "as double")
+        XCTAssertEqual(try? json.string("exceedsInt32Max"), anyValueExceedingInt32Max.description, "as string")
+        XCTAssertNotEqual(anyValueExceedingInt32Max, Int64(try! json.double("exceedsInt32Max")), "as double to int64")
+    }
+
+    // This test should also be run on the iPhone 5 simulator to check 32-bit support.
+    func testLargeIntResultsInStringOrIntWithFreddyParser() {
+        let largeValue = "1472861857112"
+        let expectedResult = Int(largeValue) // nil if on 32-bit, an Int otherwise
+
+        let value = try? JSONFromString("\(largeValue)").int()
+        XCTAssertEqual(value, expectedResult)
+        XCTAssertEqual(try? JSONFromString("\(largeValue)").string(), largeValue)
+    }
+
     // This was tripping a fatalError with the Freddy parser for 64-bit at one point:
     //     fatal error: floating point value can not be converted to Int because it is greater than Int.max
     // because we assumed the double would be in range of Int.