Thoroughly document all methods in YOLO.h

Tag 10

LICENSE

@@ -0,0 +1,6 @@
+I, Max Howell the copyright holder of this work, hereby release it into
+the public domain. This applies worldwide.
+
+In case this is not legally possible, I grant any entity the right to
+use this work for any purpose, without any conditions, unless such
+conditions are required by law.

NSDictionary+extend.m

@@ -2,19 +2,12 @@
 
 @implementation NSDictionary (YOLO)
 
-- (NSDictionary *(^)(id, ...))extend {
-    return ^NSDictionary *(NSDictionary *key, ...) {
+- (NSDictionary *(^)(NSDictionary *))extend {
+    return ^NSDictionary *(NSDictionary *key) {
         if (!key)
             return self;
         NSMutableDictionary *cp = self.mutableCopy;
-        if ([key isKindOfClass:[NSDictionary class]]) {
-            [cp addEntriesFromDictionary:key];
-        } else {
-            va_list args;
-            va_start(args, key);
-            cp[key] = va_arg(args, id);
-            va_end(args);
-        }
+        [cp addEntriesFromDictionary:key];
         return cp.copy;
     };
 }