Support patching the dSYM's plist file

[richardszalay]

The release version (CFBundleShortVersionString) also exists in a plist inside the dSYM.zip. When uploading to hockeyapp with upload_dsym_only, that is the only source of the version number. As such, act should support applying changes to dSYM files, possibly via include_dsym option.

It would also need a dsym_path option to allow the path to be overriden (we can guess the default based on the ipa name)