WSDL: pass error from parsing XML as-is, not only its message (#1022)

By passing only error's message, callee losses information about stack,
which is helpful in debugging. Besides, passing string as error breaks
mocha. (See mochajs/mocha#3320)

lib/wsdl.js

@@ -1047,7 +1047,7 @@ var WSDL = function(definition, uri, options) {
     try {
       fromFunc.call(self, definition);
     } catch (e) {
-      return self.callback(e.message);
+      return self.callback(e);
     }
 
     self.processIncludes(function(err) {

test/wsdl-test.js

@@ -51,6 +51,20 @@ wsdlStrictTests['should catch parse error'] = function(done) {
   });
 };
 
+wsdlNonStrictTests['should not give error as string'] = function(done) {
+  soap.createClient(__dirname+'/wsdl/bad.txt', function(err) {
+    assert.notEqual(typeof err, 'string');
+    done();
+  });
+};
+
+wsdlStrictTests['should not give error as string'] = function(done) {
+  soap.createClient(__dirname+'/wsdl/bad.txt', function(err) {
+    assert.notEqual(typeof err, 'string');
+    done();
+  });
+};
+
 wsdlStrictTests['should parse external wsdl'] = function(done) {
   soap.createClient(__dirname+'/wsdl/wsdlImport/main.wsdl', {strict: true}, function(err, client){
     assert.ifError(err);