CHANGELOG: add an entry about resolve showing how to continue evolve

test: explicitly run HGEDITOR shell command with `sh` Otherwise Windows pops up the "What program do you want to use to open this?" dialog.

test: conditionalize blackbox output for Windows

branching: merge with stable

compat: add wrapper for logcmdutil functions These classes and functions were bulk-renamed at hg c8e2d6ed1f9e.

evolve: store the revs to be processed in the evolvestate This will help us in getting a full functional `hg evolve` where `hg evolve --continue` does not only continue one changeset.

evolve: store the replacements in the evolvestate This will greatly help when we will be implementing `hg evolve --abort`.

evolve: store the target category in evolvestate

evolvecmd: use the evolvestate object passed as argument in _solveunstable Earlier if get a merge conflict, we used to initialize a new evolvestate object and used to save it. Let's start using the state object which we get in as argument as that will contain more data about the state.

evolvecmd: pass evolvestate object to _solve* functions This patchs adds an argument evolvestate to _solve* functions. This will help us in having one evolvestate object which we can pass around various functions and keep storing what's going on.