Templates should not reference _.escape if "escape" delimiters are not used. [closes #484]

lodash.js

@@ -6874,7 +6874,8 @@
           importsKeys = iteratorTemplate ? keys(imports) : ['_'],
           importsValues = iteratorTemplate ? values(imports) : [lodash];
 
-      var isEvaluating,
+      var isEscaping,
+          isEvaluating,
           index = 0,
           interpolate = options.interpolate || reNoMatch,
           source = "__p += '";
@@ -6895,6 +6896,7 @@
 
         // replace delimiters with snippets
         if (escapeValue) {
+          isEscaping = true;
           source += "' +\n__e(" + escapeValue + ") +\n'";
         }
         if (evaluateValue) {
@@ -6915,12 +6917,9 @@
 
       // if `variable` is not specified, wrap a with-statement around the generated
       // code to add the data object to the top of the scope chain
-      var variable = options.variable,
-          hasVariable = variable;
-
-      if (!hasVariable) {
-        variable = 'obj';
-        source = 'with (' + variable + ') {\n' + source + '\n}\n';
+      var variable = options.variable;
+      if (!variable) {
+        source = 'with (obj) {\n' + source + '\n}\n';
       }
       // cleanup code by stripping empty strings
       source = (isEvaluating ? source.replace(reEmptyStringLeading, '') : source)
@@ -6928,9 +6927,16 @@
         .replace(reEmptyStringTrailing, '$1;');
 
       // frame code as the function body
-      source = 'function(' + variable + ') {\n' +
-        (hasVariable ? '' : variable + ' || (' + variable + ' = {});\n') +
-        "var __t, __p = '', __e = _.escape" +
+      source = 'function(' + (variable || 'obj') + ') {\n' +
+        (variable
+          ? ''
+          : 'obj || (obj = {});\n'
+        ) +
+        "var __t, __p = ''" +
+        (isEscaping
+           ? ', __e = _.escape'
+           : ''
+        ) +
         (isEvaluating
           ? ', __j = Array.prototype.join;\n' +
             "function print() { __p += __j.call(arguments, '') }\n"