color: update main documentation Now that the feature no longer lives in the extension, we document it in the help of the core config. This include the new 'ui.color' option introduced in the previous changesets. As a result the color extensions can now be deprecated. This is a documentation patch only; color is still disabled by default.

pager: drop the 'color' dependant code The 'color' implementation is in core and no longer wrap '_runcommand'. We drop the extra complexity.

color: cleanup 'debugcolor' logic Now that style are carried by the 'ui' object, we no longer need complicated logic to restore the original style. We just need to copy the 'ui' and work on the copied version.

color: move 'debugcolor' into the 'debugcommands' modules This is the last bits we needed to move out of the extensions. 'hgext/color.py' now only contains logic to changes the default color behavior to 'auto'. However, more cleanups are on the way and we need to document the new config directly in core.

merge with stable

worker: flush messages written by child processes before exit I found some child outputs were lost while testing the previous patch. Since os._exit() does nothing special, we need to do that explicitly.

worker: add basic test to ensure child processes are managed well This should catch the bug fixed by "worker: ignore meaningless exit status indication returned by os.waitpid()." Before, worker.py was untested since test repositories are relatively small.

color: rename '_styles' to '_defaultstyles' for clarity This should make it clear the dict is only used for new config. Extensions should not modify it directly anyway since we have 'extraloader' logic for loading '_styles' too.

color: move 'styles' definition on the 'ui' object Same logic as for '_terminfoparams'. The content depends on the config so it should be specific to each 'ui instance.

color: pass 'ui' to 'win32print' Same logic as before,'win32print' relies on some data we will move on the 'ui' object soon, we update the API beforehand for clarity.