Refactor Makefiles.

Change-Id: I4cae1c91ddd25c0aef5f8286488c47863639824e
Signed-off-by: Wei-Chung Wen <morisato3711@gmail.com>
Add new Makefile target "install".

Change-Id: I371d5d5840393d115fd8ea09d9f0b17f475b00c4
Signed-off-by: Wei-Chung Wen <morisato3711@gmail.com>