Bug#864387: please update Yacas to version 1.6.1

[Adam Dingle]

Package: yacas
Version: 1.3.6-2

Debian unstable currently includes Yacas 1.3.6, which is 2-1/2 years 
old. Please update to the latest version, 1.6.1:

http://www.yacas.org/getting_started/downloads/