localrepo: use "self.wvfs.join()" instead of "os.path.join()" As a part of migration to vfs, this patch uses "self.wvfs.join()" instead of "os.path.join()", while initialization of fields in the constructor of "localrepository" class.

localrepo: use path expansion API via vfs As a part of migration to vfs, this patch moves path expansion API invocations in the constructor of "localrepository" to the constructor of "opener", because the root path to the repository is very important to handle paths using non-ASCII characters correctly. This patch also rearrange initialization order of "wvfs" field, because it is required to initialize "self.root".