Add support for Swift Package Manager

Only `swift build` on macOS is supported atm. `swift test` and Linux platform are not supported yet.

Author: ikesyo

.gitignore

@@ -15,4 +15,8 @@ profile
 *.moved-aside
 PlaygroundUtility.remap
 
+# SwiftPM
+.build
+
+# Carthage
 Carthage/Build

.swift-version

@@ -0,0 +1 @@
+3.0-PREVIEW-4

Package.swift

@@ -0,0 +1,24 @@
+import PackageDescription
+
+let excludes: [String]
+#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
+    excludes = [
+        "Sources/Deprecations+Removals.swift",
+        "Sources/ObjectiveCBridging.swift"
+    ]
+#else
+    excludes = [
+        "Sources/Deprecations+Removals.swift",
+        "Sources/DynamicProperty.swift",
+        "Sources/NSObject+KeyValueObserving.swift",
+        "Sources/ObjectiveCBridging.swift"
+    ]
+#endif
+
+let package = Package(
+    name: "ReactiveCocoa",
+    dependencies: [
+        .Package(url: "https://github.com/antitypical/Result.git", "3.0.0-alpha.2")
+    ],
+    exclude: excludes
+)

ReactiveCocoa/Swift/Deprecations+Removals.swift

@@ -1,3 +1,4 @@
+import Foundation
 import enum Result.NoError
 
 // MARK: Removed Types and APIs in ReactiveCocoa 5.0.

ReactiveCocoa/Swift/Lifetime.swift

@@ -1,3 +1,4 @@
+import Foundation
 import enum Result.NoError
 
 /// Represents the lifetime of an object, and provides a hook to observe when
@@ -48,6 +49,8 @@ public final class Lifetime {
 	}
 }
 
+#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
+
 private var lifetimeKey: UInt8 = 0
 private var lifetimeTokenKey: UInt8 = 0
 
@@ -70,3 +73,5 @@ extension NSObject {
 		return lifetime
 	}
 }
+
+#endif

Sources

@@ -0,0 +1 @@
+ReactiveCocoa/Swift/