remove doubled words, e.g., s/to to/to/, and fix related typos

I found that some doubled words had snuck back into projects from which
I'd already removed them, so now there's a "syntax-check" makefile rule in
gnulib to help prevent recurrence.

Running the command below spotted a few in git, too:

  git ls-files | xargs perl -0777 -n \
    -e 'while (/\b(then?|[iao]n|i[fst]|but|f?or|at|and|[dt])\s+\1\b/gims)' \
    -e '{$n=($` =~ tr/\n/\n/ + 1); ($v=$&)=~s/\n/\\n/g;' \
    -e 'print "$ARGV:$n:$v\n"}'

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
[wking@tremily.us: only apply SubmittingPatches portion of the
original patch since I'm pulling out only the D-C-O portion of
SubmittingPatches]
Signed-off-by: W. Trevor King <wking@tremily.us>

SubmittingPatches: Document some extra tags used in commit messages

Document the meanings of the tags "Reported-by:", "Acked-by:",
"Reviewed-by:" and "Tested-by:" clearly. Also mention that the user is
free to use any custom tags.

Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Liked-by: Sverre Rabbelier <srabbelier@gmail.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
[wking@tremily.us: removed diff context to merge with Linux kernel
version]
Signed-off-by: W. Trevor King <wking@tremily.us>

SubmittingPatches: mention the usage of real name in Signed-off-by: lines

Especially with something that is supposed to hopefully have some legal
value down the line if somebody starts making noises, it really would be
nice to have a real person to associate things with. Suggest this in the
SubmittingPatches document.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/SubmittingPatches: What's Acked-by and Tested-by?

We used to talk about "internal company procedures", but this
document is about submitting patches to the git mailing list.

More useful information is when to say Acked-by: and Tested-by:.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
[wking@tremily.us: removed diff context to merge with Linux kernel
version]
Signed-off-by: W. Trevor King <wking@tremily.us>

Teach SubmittingPatches about git-commit -s

As discussed on git mailing list let's teach the reader about
the possiblity to have automatically signed off the commit running
the git-commit -s command

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[wking@tremily.us: removed diff context to merge with Linux kernel
version]
Signed-off-by: W. Trevor King <wking@tremily.us>

Documentation: fix spelling error in SubmittingPatches

Fixed a spelling error.

Signed-off-by: Zac Storer <zac.3.14159@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

doc: add suggestions about good practises for maintainers

Suggest how to deal with patch modifications caused by
merging or back-porting when you're a maintainer.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[wking@tremily.us: removed diff context since I'm pulling out only the
D-C-O portion of SubmittingPatches]
Signed-off-by: W. Trevor King <wking@tremily.us>

We can not allow anonymous contributions to the kernel

The DCO does not mean anything if we allow anonymous contributors to the
kernel.  As this is an open source project, we need to do everything in the
open.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

DCO: use IANA-reserved second level domain name

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Update DCO ("signoff") rules to 1.1

This adds a clause that notes explicitly that the person doing the
sign-off knows that the project (and his sign-off) is public and will
possibly get archived and re-distributed.

Start documenting the sign-off procedure in SubmittingPatches

We already have over 200 sign-off lines in the kernel, so
let's document the thing, even if discussion may still be
on-going.

[wking@tremily.us: removed diff context since I'm pulling out only the
D-C-O portion of SubmittingPatches]
Signed-off-by: W. Trevor King <wking@tremily.us>