branching: merge with stable

grab: preserve phase of the grabbed changeset This patch fixes the wrong behavior of loosing secret phase of the grabbed changeset.

tests: add a test showing grabbing of secret changeset turn it into draft This patch adds a test showing wrong behavior of `hg grab` command which looses the secret phase while grabbing a secret changeset.

grab: add grab info to cmdutil.afterresolvedstates This will help us in showing how to continue the grab when user resolves all the conflicts.

evolve: add evolve info to cmdutil.afterresolvedstates Adding evolve info to cmdutil.afterresolvedstate will improve the ui when we run into merge conflicts while evolving. Once we resolve all the conflicts using `hg resolve`, this will show a message saying "continue: hg evolve --continue". Other extensions like rebase and shelve also use it and it's very helpful.

doc: add link to roadmap Add a link to the Evolution roadmap in the main page of the documentation.

evolve: move the evolve command to evolvecmd.py This patch moves finishes the code movement by moving the evolve command to evolvecmd.py.

evolve: move _orderrevs() function evolvecmd.py _orderrevs() is a function which is used to order the revs in which the instability needs to be solved if we have multiple revisions to resolve.

evolve: move builddependencies() and _singlesuccessor() to utility module The builddependencies() and _singlesuccessor() function are very useful functions and can be used at a lot of places. They are also used in topic extension also, so let's move them to utility. However moving them to utility won't help anything in the topic extension.

utility: move MultipleSuccessorsError from __init__.py The MultipleSuccessorsError is required in multiple modules in upcoming patches, so let's move it to utility first.