Mpp::Signature::xml -- a signature class that ignores insignificant changes and comments
This signature method signs the essence of an xml document. Quoting style and order of attributes are ignored, as is the way empty tags are represented and whether special characters are protected as entities or in a CDATA section.
Whitespace around tags is ignored completely whereas any whitespace elsewhere is considered as just one space. This is usually the right thing to do for config files, but if you don't want that, use xml-space instead.