Squashed commit of the following:

commit bd6e213f1a585fde5a0a30dfe3f4a69f83254d5d
Author: Tomo Hori <horit@stelab.nagoya-u.ac.jp>
Date:   Mon Aug 11 20:02:18 2014 +0900

    fixed bugs causing the misinterpolation of hatched color tables

commit 56252e94a97b778203b94f95482a81bcde2470a8
Author: Tomo Hori <horit@stelab.nagoya-u.ac.jp>
Date:   Thu Aug 7 19:35:25 2014 +0900

    implemented hatched_width keyword to loadct_sd

commit 75451c7c5335a998f2ff93c749fd7c41a387cdaa
Author: Tomo Hori <horit@stelab.nagoya-u.ac.jp>
Date:   Thu Aug 7 14:58:28 2014 +0900

    implemented center_hatched keyword to loadct_sd