utf8.c: partially update to version 6.3

Unicode 6.3 defines more code points as combining or accents.  For
example, the character "ö" could be expressed as an "o" followed by
U+0308 COMBINING DIARESIS (aka umlaut, double-dot-above).  We should
consider that such a sequence of two codepoints occupies one display
column for the alignment purposes, and for that, git_wcwidth()
should return 0 for them.  Affected codepoints are:

    U+0358..U+035C
    U+0487
    U+05A2, U+05BA, U+05C5, U+05C7
    U+0604, U+0616..U+061A, U+0659..U+065F

Earlier unicode standards had defined these as "reserved".

Only the range 0..U+07FF has been checked to see which codepoints
need to be marked as 0-width while preparing for this commit; more
updates may be needed.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test: fix t7001 cp to use POSIX options

Since 11502468 and 04c1ee57 (both first appearing in v1.8.5), the
t7001-mv test has used "cp -a" to perform a copy in several of the
tests.

However, the "-a" option is not required for a POSIX cp utility and
some platforms' cp utilities do not support it.

The POSIX equivalent of -a is -R -P -p.

Change "cp -a" to "cp -R -P -p" so that the t7001-mv test works
on systems with a cp utility that only implements the POSIX
required set of options and not the "-a" option.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test: fix t5560 on FreeBSD

Since fd0a8c2e (first appearing in v1.7.0), the
t/t5560-http-backend-noserver.sh test has used a backslash escape
inside a ${} expansion in order to specify a literal '?' character.

Unfortunately the FreeBSD /bin/sh does not interpret this correctly.

In a POSIX compliant shell, the following:

x='one?two?three'
echo "${x#*\?}"

Would be expected to produce this:

two?three

When using the FreeBSD /bin/sh instead you get this:

one?two?three

In fact the FreeBSD /bin/sh treats the backslash as a literal
character to match so that this:

y='one\two\three'
echo "${y#*\?}"

Produces this unexpected value:

wo\three

In this case the backslash is not only treated literally, it also
fails to defeat the special meaning of the '?' character.

Instead, we can use the [...] construct to defeat the special meaning
of the '?' character and match it exactly in a way that works for the
FreeBSD /bin/sh as well as other POSIX /bin/sh implementations.

Changing the example like so:

x='one?two?three'
echo "${x#*[?]}"

Produces the expected output using the FreeBSD /bin/sh.

Therefore, change the use of \? to [?] in order to be compatible with
the FreeBSD /bin/sh which allows t/t5560-http-backend-noserver.sh to
pass on FreeBSD again.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'km/avoid-bs-in-shell-glob' into next

Portability fix.

* km/avoid-bs-in-shell-glob:
  test: fix t5560 on FreeBSD
Merge branch 'km/avoid-cp-a' into next

Portability fix.

* km/avoid-cp-a:
  test: fix t7001 cp to use POSIX options
Merge branch 'tb/unicode-6.3-zero-width' into next

Teach our display-column-counting logic about decomposed umlauts
and friends.

* tb/unicode-6.3-zero-width:
  utf8.c: partially update to version 6.3