Updating octave to 3.8.1

(cherry picked from commit 43ed6b8f62d6705156c77b84c21cf5f0618a0b9e)
octave: Update to 3.8.2.

Also change "," placement to be consistent and remove unnecessary let.

(cherry picked from commit 05b83fe6a23e5ca0b531fb47269c419d6a549d7b)
Enable parallel building in octave.

Let's wait for problems.