vfsproxy: inherit the `createmode` attribute too It is an important part of the API when creating directory. We will need it in the next changeset.

revlog: test more complex file pattern for revlog split There have been a report of failure while splitting revlog. The file name involved was important. The pattern involved here are not problematic, but it help to setup the machinery to test multiple files, the actual fix and problematic file will arrive in a later changeset.

repo-upgrade: write new requirement before upgrading the dirstate This will prevent a small race condition where another hg process still believes the repo is dirstate-v1 during the upgrade process. This is good to have, but it is not a proper fix for the underlying problem. There is code that assumes a requirement means a usage, e.g. having the `generaldelta` requirement would imply *all* revlogs to use general delta, but it's not true, it simply means that the repository advertises to the client it needs to understand `generaldelta` in order to read the repo. In the case of the dirstate, having the requirement *technically* should always be the same as using dirstate-v2, since there is only one dirstate and requirements should be as minimal as possible. However, we should not assume this and make the code more robust in a future patch (series).

rhg: correctly relativize copy source path

rhg: don't print copy source when --no-status is passed

tests: add test for status copy source formatting

fix: highlight the required configuration and behavior of the fixer tools The problem is that `hg help fix` didn't mention *how* to configure the tools, and while I knew that `{rootpath}` existed in the configuration, I missed that the tools require reading content from stdin. (I configured `gofmt` to use `{rootpath}`, and that had the effect of squashing all changes in a file at `.` into the first commit and emptying that content from its descendants.) Basically all this does is put a pointer in the default (command level) help to the extension level help that mentions the configuration, and moves the extension level help that documents reading from stdin and writing to stdout to the top to give it more prominence. The last sentence is adjusted a bit to reflect the new location.

debug-delta: add minimal documentation for `devel.bundle-delta` option So the next person won't have to grep the code to know what it is doing.

delta-find: simply code that is now never invoqued without general delta Finish early in on-general delta case mean a lot of code can assume that general delta is not enabled.

delta-find: add a simple safeguard to prevent bad non-general-delta This make it easier to catch request to build delta that does not make sense in the general delta world. It seems better to raise a programming error than to corrupt the repository.