Update fp map for assignment methods and set methods. [closes #1754]

lib/fp/mapping.js

@@ -109,7 +109,8 @@ module.exports = {
     'clamp': [2, 0, 1],
     'reduce': [2, 0, 1],
     'reduceRight': [2, 0, 1],
-    'setWith': [3, 2, 1, 0],
+    'set': [2, 0, 1],
+    'setWith': [3, 1, 2, 0],
     'slice': [2, 0, 1],
     'transform': [2, 0, 1]
   },
@@ -153,8 +154,14 @@ module.exports = {
 
   /** Used to track methods that skip `_.rearg`. */
   'skipReargMap': {
+    'assign': true,
+    'assignIn': true,
+    'defaults': true,
+    'defaultsDeep': true,
     'difference': true,
+    'extend': true,
     'matchesProperty': true,
+    'merge': true,
     'random': true,
     'range': true,
     'rangeRight': true,