l10n: git.pot: v2.0.0 round 1 (45 new, 28 removed)

Generate po/git.pot from v2.0.0-rc0 for git v2.0.0 l10n round 1.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
l10n: zh_CN.po: translate 45 new messages (2228t0f0u)

Translations for git v2.0.0-rc0.  Also correct translatioins on relative
date in date.c with help from Brian Gesiak ($gmane/246390).

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
bugfix: fix broken time_buf paddings for git-blame

Command `git blame --date relative` aligns the date field with a
fixed-width (defined by blame_date_width), and if time_str is shorter
than that, it adds spaces for padding.  But there are two bugs in the
following codes:

        time_len = strlen(time_str);
        ...
        memset(time_buf + time_len, ' ', blame_date_width - time_len);

1. The type of blame_date_width is size_t, which is unsigned.  If
   time_len is greater than blame_date_width, the result of
   "blame_date_width - time_len" will never be a negative number, but a
   really big positive number, and will cause memory overwrite.

   This bug can be triggered if either l10n message for function
   show_date_relative() in date.c is longer than 30 characters, then
   `git blame --date relative` may exit abnormally.

2. When show blame information with relative time, the UTF-8 characters
   in time_str will break the alignment of columns after the date field.
   This is because the time_buf padding with spaces should have a
   constant display width, not a fixed strlen size.  So we should call
   utf8_strwidth() instead of strlen() for width calibration.

Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
blame: use a helper to get suitable blame_date_width

When show date in relative date format for git-blame, the max display
width of datetime is set as the length of the string "Thu Oct 19
16:00:04 2006 -0700" (30 characters long).  But actually the max width
for C locale is only 22 (the length of string "x years, xx months ago").
And for other locale, it maybe smaller.  E.g. For Chinese locale, only
needs a half (16-character width).

Add a helper function date_relative_maxwidth() to date.c, which returns
the suitable display width for the relative date field in different
locale.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>