Small improvement with auxiliary constants.
Improved name of indicator-field for literals.

Renamed "status" -> "unassigned".
Now the unassigned fields for literals v,-v is only used for v.
Now positive literals come first.

0 = neutral element, and also for the vdW-instances the positive literals
are more common.
Very simple timing of tawSolver.

A simple start for the long-outstanding timing facility.
Added general timing-target for oklib-building.