Makefile clean
Makefile simpler

Squashed commit of the following:

commit a34882ab6a925de76c2787c503a33d0246920b1e
Author: Yuki Inoue <inouetakahiroki@gmail.com>
Date:   Sat Jan 12 08:23:33 2013 +0900

    rechanged g++ to c++

commit 1334defd31be18181f428451c9ac2ccd87328930
Author: Yuki Inoue <inouetakahiroki@gmail.com>
Date:   Sat Jan 12 08:18:34 2013 +0900

    bug fix

commit a4635c19a945ab413c3e1c8c71892a662d752c74
Merge: 53692b8 cd99b61
Author: Yuki Inoue <inouetakahiroki@gmail.com>
Date:   Sat Jan 12 08:15:40 2013 +0900

    Merge branch 'master' into dev

    Conflicts:
    	Makefile

commit 53692b80a2831be153e92fc814e1a8031b66f665
Author: Yuki Inoue <inouetakahiroki@gmail.com>
Date:   Sat Jan 12 07:43:14 2013 +0900

    Makefile fix