Add Swift Package Manager support

Author: kylef

.gitignore

@@ -1 +1,2 @@
 .conche/
+/.build/

Commander.podspec.json

@@ -15,13 +15,13 @@
     "git": "https://github.com/kylef/Commander.git",
     "tag": "0.3.0"
   },
-  "source_files": "Commander/*.{h,swift}",
+  "source_files": "Sources/*.{h,swift}",
   "platforms": {
     "ios": "8.0",
     "osx": "10.9"
   },
   "test_specification": {
-    "source_files": "CommanderSpecs/*Spec.swift",
+    "source_files": "Specs/*Spec.swift",
     "dependencies": {
       "Spectre": [ "~> 0.5.0" ]
     }

Commander/Commander.h

@@ -0,0 +1,5 @@
+import PackageDescription
+
+let package = Package(
+  name: "Commander"
+)

Commander/Info.plist

@@ -171,13 +171,14 @@ public final class ArgumentParser : ArgumentConvertible, CustomStringConvertible
     var index = 0
     for argument in arguments {
       switch argument {
-      case .Flag(var option):
-        if option.contains(flag) {
-          option.remove(flag)
+      case .Flag(let option):
+        var options = option
+        if options.contains(flag) {
+          options.remove(flag)
           arguments.removeAtIndex(index)
 
-          if !option.isEmpty {
-            arguments.insert(.Flag(option), atIndex: index)
+          if !options.isEmpty {
+            arguments.insert(.Flag(options), atIndex: index)
           }
           return true
         }