added _.isFunction defintion

lodash/lodash-tests.ts

@@ -623,6 +623,8 @@ result = <boolean>_.isFinite(true);
 result = <boolean>_.isFinite('');
 result = <boolean>_.isFinite(Infinity);
 
+result = <boolean>_.isFunction(_);
+
 var mergeNames = {
   'stooges': [
     { 'name': 'moe' },

lodash/lodash.d.ts

@@ -2426,6 +2426,13 @@ declare module _ {
 	**/
 	export function isFinite(value: any): boolean;
 
+	/**
+	* Checks if value is a function.
+	* @param value The value to check.
+	* @return True if the value is a function, else false.
+	**/
+	export function isFunction(value: any): boolean;
+
 	/**
 	* Recursively merges own enumerable properties of the source object(s), that don't resolve 
 	* to undefined into the destination object. Subsequent sources will overwrite property 
@@ -2653,13 +2660,6 @@ declare module _ {
 	**/
 	export function isObject(object: any): boolean;
 
-	/**
-	* Returns true if object is a Function.
-	* @param object Check if this object is a Function.
-	* @return True if `object` is a Function, otherwise false.
-	**/
-	export function isFunction(object: any): boolean;
-
 	/**
 	* Returns true if object is a String.
 	* @param object Check if this object is a String.