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.

evolvecmd: move more core from __init__.py to evolvecmd.py We are done with moving helper code, we will now be moving the evolve command in the new module.

evolvecmd: move code from __init__.py to evolvecmd.py

evolvecmd: move more code from __init__.py to evolvecmd.py We are now very close to have most of the evolve related code in evolvecmd.py.

evolvecmd: move more chunks of code from __init__.py to evolvecmd.py

evolvecmd: move more functions from __init__.py to evolvecmd.py If things are looking ugly, hold on.

evolvecmd: introduce a new module to handle `hg evolve` related code __init__.py is to cluttered with wrapping and all, it's better to move code related to evolve command to new a module which will help us in great refactoring and introducing nice and better flow of data through functions. There is a temporary import cycle is introduced which will be fixed in the series.

evolve: remove not required calls to phases.retractboundary() To make sure phases are preserved during evolve, we started using the phases.new-commit config option. Now we don't need to call phases.retractboundary(). Let's remove the redundant code.

evolve: store the replacements occurred during `hg evolve` at top level This patch starts storing the replacements made during the `hg evolve` command. The current dictionary is not used anywhere but will be used in future as we want to introduce abort functionality, so we want to delay writing of obsmarkers, storing these exchanges in statefile etc.

evolve: make the _solve* functions return a tuple This patch makes _solve* functions return a tuple which will contain information about whether we were able to solve the instability and if yes, then what was the newnode. For more details about tuple, look the fn docs added. There was some refactoring required in next command because of change in return values. This also leds to omitting the wdir update message in case of dry-run which is good.

evolvestate: rename the file to state.py and class name to cmdstate The evolvestate.py and the evolvestate class in it were introduced to help `hg evolve` grow continue and abort options. But the class and it's API can be easily used to store state information for other state files like we stored the information for grab state in the previous commit. Let's rename the the file and class.

branching: merge with stable

update: show "use 'hg evolve' to..." hint iff evolve command enabled Before this patch, one had to enable *all* commands (by including "allnewcommands" in the experimental.evolution config) for the hint to be shown.

obslog: drop period from summary line in accordance with convention