update PKGBUILD

put hime-git.install back
move README to markdown syntax

add Archlinux part
pick up modifications from gcin 2.8

https://github.com/czchen/debian-gcin/commit/1bb7f2c3a683ff9043afd958c98fba5c8a3a6441
Merge pull request #490 from xatier/master

update Archlinux PKGBUILD and move README to markdown
fix issue #482
Merge pull request #493 from hime-ime/issue#482#491

fix issue #482
Merge pull request #492 from xatier/anthy-pick

pick up modifications from gcin 2.8
Defined _XSERVER64 in header

See [0], the _XSERVER64 affects the struct HIME_client_handle_S, so it
shall be defined alone with HIME_client_handle_S to prevent struct
conflict.

[0] https://bugs.debian.org/750375
Merge pull request #496 from czchen/bugfix/xserver64

Defined _XSERVER64 in header
Merge remote-tracking branch 'up/master'