l10n: git.pot: v1.8.4 round 1 (99 new, 46 removed)

Generate po/git.pot from v1.8.4-rc0 for git v1.8.4 l10n round 1.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
l10n: zh_CN.po: translate 99 messages (2133t0f0u)

Translate 99 new messages came from git.pot update in 28b3cff
(l10n: git.pot: v1.8.4 round 1 (99 new, 46 removed)).

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>