store: rename field name from "opener" to "vfs" in internal classes for fncache These fields are used only in store module, so keeping "self.opener" for backward compatibility like as "localrepository" class is not needed.

store: rename argument name from "op"(ener) to "vfs"

verify: rename "hasmanifest" variable for source code readability Before this patch, there are two ambiguous variables: "havemf" and "hasmanifest". "havemf" means whether there are any "manifest" entries. "hasmanifest" means whether there are any "changelog" entries referring to "manifest" entry. This patch renames from "hasmanifest" to "refersmf" to clear difference from "havemf".

verify: use appropriate local variable in "checkentry()" Before this patch, "checkentry()" internal function uses both "node"(argument of itself) and "n"(defined in outer of it) variables. Because all callers of "checkentry()" use "n" to refer the object which is passed to "checkentry()" as "node", both can refer same object in "checkentry()". So, "checkentry()" works correctly. But such usage is not good for independence of "checkentry()". This patch replaces "n" in "checkentry()" with "node".

verify: use appropriate node information to show verification error Before this patch, verify module shows verification error message below: unknown parent 2 <HASH_OF_P2> of <HASH_OF_P1> even though it should show: unknown parent 2 <HASH_OF_P2> of <HASH_OF_TARGET> This patch uses appropriate node information.

help: add information about recovery from corruption to help of "verify" Before this patch, there is no information about what users should (or can) do for recovery from corruption of repositories. This patch adds URL of the Mercurial Wiki page explaining about recovery from corruption.