Apple have announced the release of a developer build of the next major version of the Mac operating system, Mountain Lion. The build is already available to Mac Developer Program members and will be released in the Mac App Store late this summer. Apple states that Mountain Lion contains over 100 new features and introduces several new apps and features to the Mac that already exist in iOS for the iPhone, iPod touch and iPad. Mountain Lion will include versions of the Messages, Reminders, Notes, and Game Center apps originally available in iOS. Mountain Lion will also include deeper integration with iCloud for email, contacts, calendar, and document synchronization, a…