update: accept --merge to allow merging across topo branches (issue5125)

merge: combine the "merge" cases in docstring table

merge: combine "dirty" cases in docstring table

merge: clarify non-linear default updates in docstring table Non-linear updates won't happen by default, regardless of -c/-C.

merge: combine the two "can't happen" cases in docstring table

merge: move "incompatible options" case first in docstring table

merge: make "linear" an input in docstring table Instead of having two ouputs, it seem simpler to have an addition input. This will allow further simplification.

merge: drop redundant column in docstring table The "same" and "cross" columns now have the same values, so let's combine them into "non-linear".

merge: drop obsolete non-linear cases from docstring table Since 6b1fc09c699a (update: change default destination to tipmost descendant (issue4673) (BC), 2016-02-02), non-linear updates can no longer happen if the user doesn't specify a destination, so we can drop these case from the table in the docstring of merge.update().

revert: move code dealing with deletions closer together

ui: fix configlist on Python 3 Since we're working on bytestrings, we have to use [offset:offset+1] to get consistent behavior on Python 2 and 3. I've only tested the _parse_plain closure, not the _parse_quote one, but I have no real reason to expect the latter to be broken since the fixes were fairly mechanical.

config: pass some optional args as keywords This makes it a little more obvious that self.read is being passed as include, which took me a moment to figure out.

config: load included config files in binary mode I guess we've been getting lucky that this works in Python 2. This fixes loading included config files in Python 3 (it used to fail on the "somebody set up us the BOM" check.)

manifest: remove _repo from manifestctx objects We were storing the repo on the manifestctx objects so that they could access the manifestlog via repo.manifestlog, which would refresh the structure if it became out of date. This caused probems however when we want to have multiple manifest logs in memory at once, like when transitioning to tree manifest from flat manifests, since a tree manifest would try to access sub-trees via repo.manifestlog[node], which was the flat manifest. The solution is to just not store the repo, and instead store the manifestlog that created this context. This removes the invalidation when the in memory manifestlog becomes out of date, but people should probably not be keeping ctx's around that long anyway.

phases: remove experimental.nativephaseskillswitch The native code has been used for a long time. Therefore drop the experimental config option.