fix(osx): fix build on OSX

OSX uses clang by default, and there were a number of changes in
order to get things building there. As an added bonus, I've cleaned
up a bunch of things given that clang is somewhat stricter out of
the box. In particular these changes are included:

  - switch to using constructor functions rather than constructor
    templates where appropriate

  - a few bug fixes with signed vs unsigned integer comparison

  - switched event support to use an EventEmitter implementation
    rather than callbacks

binding.gyp

@@ -33,6 +33,11 @@
             '-std=c++11',
             '<!@(pkg-config --cflags libvirt)'
           ],
+        }],
+        ['OS=="mac"', {
+          'xcode_settings': {
+            'GCC_ENABLE_CPP_RTTI': 'YES'
+          }
         }]
       ]
     }

lib/index.js

@@ -1,7 +1,15 @@
 'use strict';
 
 var libvirt = require('bindings')('libvirt'),
-    Promise = require("bluebird");
+    Promise = require("bluebird"),
+    EventEmitter = require('events').EventEmitter;
+
+// extend prototype
+function inherits(target, source) {
+    for (var k in source.prototype) {
+        target.prototype[k] = source.prototype[k];
+    }
+}
 
 Promise.promisifyAll(libvirt.Hypervisor.prototype);
 Promise.promisifyAll(libvirt.Domain.prototype);
@@ -13,6 +21,8 @@ Promise.promisifyAll(libvirt.Secret.prototype);
 Promise.promisifyAll(libvirt.StoragePool.prototype);
 Promise.promisifyAll(libvirt.StorageVolume.prototype);
 
+inherits(libvirt.Domain, EventEmitter);
+
 /*
  * A helper method returning an 'all domains' promise.
  */
@@ -33,12 +43,21 @@ libvirt.Hypervisor.prototype.getAllDomains = function() {
   .then(function(domains) {
     return domains.concat(defined);
   });
-}
+};
 
-module.exports = {
-  Promise: Promise,
-  startEventLoop: libvirt.setupEvent,
-  createHypervisor: function(uri, options) {
-    return new libvirt.Hypervisor(uri, options);
-  }
+libvirt.Promise = Promise;
+libvirt.startEventLoop = libvirt.setupEvent,
+libvirt.createHypervisor = function(uri, options) {
+  return new libvirt.Hypervisor(uri, options);
 };
+
+module.exports = libvirt;
+
+// module.exports = {
+//   libvirt: libvirt,
+//   Promise: Promise,
+//   startEventLoop: libvirt.setupEvent,
+//   createHypervisor: function(uri, options) {
+//     return new libvirt.Hypervisor(uri, options);
+//   }
+// };