localrepo: make "undofiles()" return list of tuples "(vfs, relative filename)" Before this patch, "localrepository.undofiles()" returns list of absolute filename of undo files. This patch makes it return list of tuples "(vfs, relative filename)" to access undo files via vfs. This patch also changes "repair.strip()", which is the only user of "localrepository.undofiles()".

exchange: fix pyflakes import complaint

hgweb: override the charset attribute in the http request The default http request character set is UTF-8. If the message is not encoded in UTF-8, such as big5, it cannot be shown correctly. The 'charset' is overridden by the root document's, such that the user can select the proper encoding in the browser.