streamclone: use readexactly when reading stream v2 Yuya Nishihara pointed out that it is safer.

streamclone: rename '_emit' to '_emit2' for clarity This change was suggested by Gregory Szorc.

help: do not suggest "update --clean ." to cancel uncommitted merge Follows up 41ef02ba329b.

minifileset: note the unsupported file pattern when raising a parse error This was useful in debugging, because I stupidly quoted it out of habit from the command line. This isn't a great example that clearly shows the problem, but I don't know how to improve it. The problem *is* obvious once a complex statement or a clearly bogus string is used.

lfs: don't automatically exclude '.hg*' files from external tracking The only reasons I did this in the first place was because tracking externally seems like it would always be a mistake, and the eol extension does the same thing. Yuya and Jun thought it might be better to not do this[1], so I'll defer to them on this. If a problem with say, .hgtags or .hgeol does arise, it can be added back without breaking existing repos. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/110371.html

lfs: rename {oid} to {lfsoid} Per Yuya, for consistency with {lfspointer}. It might be slightly confusing for there to be {lfsoid} and {lfspointer.oid}. But preventing ambiguity seems more important, and the latter is controlled by the git-lfs spec.

lfs: rename {pointer} to {lfspointer} Per Martin von Zweigbergk's suggestion to keep this unambiguous, for when it is migrated to {files} and friends.

Added signature for changeset 27b6df1b5adb

Added tag 4.5-rc for changeset 27b6df1b5adb

merge with stable to begin 4.5 freeze # no-check-commit because it's a clean merge