evolve: add an help topic about evolution The text is probably bad, but this have been laying around for quite sometime (with Mercurial core in mind) lets move forward and add this to evolve.

evolve: remove _picknexttroubled It was not used anymore

evolve: warn about every skipped evolution When we could not evolve a revision, we used to silently ignore it. We now inform the user that we ignored something and tell him why (with more or less informative message).

evolve: some style fix

evolve: unify revision handling and rework error message This changesets do a massive refactoring of the way evolve select changesets to be evolve. We now use a two stages approach: 1) read command line argument and produce a list of revision to evolve. 2) evolve all these revisions. This allow a much cleaner, robust and extensible code. In the process the error message issued when there is nothing to evolve have been updated to informs about other troubles in the repository and point at useful option to solve them. The 'update' case is handled independently at the start of the function.

evolve: move the 'update' if '.' is obsolete earlier A big refactoring of the computation of the revision to evolve is coming. This case won't be handled by it, so we extract it earlier.

evolve: skip unstable changesets with multiple successorssets We were previously crashing when encountering them, but we want to be able to solve the other solvable troubles instead of stopping right there.