Added the 'is-promise' library.

is-promise/index.d.ts

@@ -0,0 +1,8 @@
+// Type definitions for is-promise
+// Project: https://github.com/then/is-promise
+// Definitions by: Daniel Rosenwasser <https://github.com/DanielRosenwasser>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+export = isPromise;
+
+declare function isPromise(obj: any): obj is PromiseLike<any>;

is-promise/is-promise-tests.ts

@@ -0,0 +1,15 @@
+import isPromise = require("./");
+
+isPromise({ then() { }});
+isPromise(null);
+isPromise({ });
+isPromise({then: true});
+
+function f(x: number | PromiseLike<number>) {
+    if (isPromise(x)) {
+        x.then;
+    }
+    else {
+        x.toExponential;
+    }
+}

is-promise/tsconfig.json

@@ -0,0 +1,19 @@
+{
+    "files": [
+        "index.d.ts",
+        "is-promise-tests.ts"
+    ],
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es6",
+        "noImplicitAny": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    }
+}