Added domain file filter & bug fixes

- Added new argument to filter files by their backup domain, such as "MediaDomain" or "HomeDomain". This can be used to filter for files from a specific application.

- Removes the encrypted file when it is properly decrypted.

- Fixed the location of initializing instance variables in the MobileBackupClient class.
Implemented writing Info.plist with plistlib.
Removed comment referencing iScavenge
When the `itunes-style` option is used, a `Manifest.mbdb` file is now generated.
Removed semi-colons
Merge pull request #3 from mattandersen/master

Better iTunes-style option, Domain filter, bug fixes