match: move _normalize() into the match class This will be overridden in an upcoming patch to also deal with dirstate normalization on case insensitive filesystems.

largefiles: always consider updatelfiles 'checked' parameter set mergeupdate already set the flag to update all. This will thus only change overriderevert and scmutilmarktouched ... where the flag effectually also were true. The test coverage thus shows no change. As the flag always is set, it is removed. This is mainly a change for keeping the code simple and consistent and correct, but it should also make it faster in many cases.