Unicode: update of combining code points

Unicode 6.3 defines the following code as combining or accents,
git_wcwidth() should return 0.

Earlier unicode standards had defined these code point as "reserved":

358 COMBINING DOT ABOVE RIGHT
359 COMBINING ASTERISK BELOW
35A COMBINING DOUBLE RING BELOW
35B COMBINING ZIGZAG ABOVE
35C COMBINING DOUBLE BREVE BELOW
487 COMBINING CYRILLIC POKRYTIE
5A2 HEBREW ACCENT ATNAH HAFUKH,
5BA HEBREW POINT HOLAM HASER FOR VAV
5C5 HEBREW MARK LOWER DOT
5C7 HEBREW POINT QAMATS QATAN
604 ARABIC SIGN SAMVAT
616 ARABIC SMALL HIGH LIGATURE ALEF WITH LAM WITH YEH
617 ARABIC SMALL HIGH ZAIN
618 ARABIC SMALL FATHA
619 ARABIC SMALL DAMMA
61A ARABIC SMALL KASRA
659 ARABIC ZWARAKAY
65A ARABIC VOWEL SIGN SMALL V ABOVE
65B ARABIC VOWEL SIGN INVERTED SMALL V ABOVE
65C ARABIC VOWEL SIGN DOT BELOW
65D ARABIC REVERSED DAMMA
65E ARABIC FATHA WITH TWO DOTS
65F ARABIC WAVY HAMZA BELOW

This commit touches only the range 300-6FF, there may be more to be updated.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'tb/unicode-6.3-zero-width' into pu

* tb/unicode-6.3-zero-width:
  Unicode: update of combining code points