repair: make "strip()" treat bundle files via vfs This patch makes "repair.strip()" treat bundle files via vfs. This patch also avoids applying "vfs.join()" on the value returned by "changegroup.writebundle()", to get relative path from "_bundle()".

changegroup: add "vfs" argument to "readbundle()" to pass relative filename

repair: make paths in "_bundle()" relative to ".hg" This patch makes paths below in "_bundle()" relative to ".hg": - backup directory ("strip-backup"), and - bundle file under backup directory "vfs" is passed to "changegroup.writebundle()" to use relative path directly. This patch applies "vfs.join()" on the value returned by "_bundle()", because the caller expect it to return absolute path. This will be changed by succeeding patch changing the caller side.