Add AppleTV modules (imge, video and login)

These AppleTV modules were originally made and submitted by @0a2940, and went through some changes by thelightcosine and me.

To verity the apple_display_image module:

- [ ] Make sure you have access to an AppleTV device. If you don't, let me know and I will return it asap.
- [ ] Have an image file ready.
- [ ] Start msfconsole, ```use auxiliary/admin/appletv/appletv_display_video```, set the appropriate options, and ```run```
- [ ] Your image should display on the appletv screen.

To verify the apple_display_video module:

- [ ] Make sure you have access to an AppleTV device. If you don't, let me know and I will return it asap.
- [ ] Set up a web server. The most ideal one is Apache. If you prefer to use something different, please read the description. It explains what works, what doesn't.
- [ ] Start msfconsole, ```use auxiliary/admin/appletv/appletv_display_video```, set the appropriate options, and ```run```
- [ ] Your video should run on the appletv screen

To verify the apple_login module:

- [ ] Make sure you have access to an AppleTV device. If you don't, let me know and I will return it asap.
- [ ] On your appletv, go to Settings -> AirPlay -> Security. Set a password on either "Onscreen Code", or "passsword" mode.
- [ ] Start msfconsole, ```use auxiliary/scanner/http/appletv_login```, set the appropriate options, and ```run```. If your password list has the right password, it should say the password is found. If you're testing the Onscreen mode, make sure to set the Onscreen datastore option to true.

@todb-r7 Since this module is related to LoginScanner, please make sure to update the scoreboard after this pull request is merged: https://github.com/rapid7/metasploit-framework/wiki/Metasploit-Loginpalooza#scorecard.