Added new viscosity models: powerLaw, HerschelBulkley.

old formulation includes the effect of gradients caused by solid body
rotation on the strain rate, while the second returns only the
irrotational part.

Changed WM_THIRD_PARTY to WM_THIRD_PARTY_DIR and added to all 'options' files that use third-party software.

#           x         0.05         0.03
#           y         0.05         0.04
#           z        0.001        0.001
#        Time
        0.005     0.130842   7.7749e-05
         0.01    0.0554095   -0.0100031
        0.015    0.0388121   -0.0115969

Added new BC (untested).

Corrected the use of the "^" product operator.

the new and more correct version 2.5.34.