suite-sparse: update to 4.2.0

Update suite-sparse to the new 4.2.0. This should fix the recent Octave
build problems.

Also change the metis dependency to use the metis4 formula instead of metis,
since SuiteSparse is not compatible with Metix 5.x.

Now uses built-in Mac make script.

Use :recommend and :option for dependencies

closes #128, closes #132, closes #139, closes #146, closes #153

Signed-off-by: Derek Thomas <derekathomas@gmail.com>
add option to disable tk as this breaks compilation.
Add keg only version 3 of ITK used for building VMTK
Add formula for vmtk

Add a formula for vmtk vmtk.org the Vascular Modeling Toolkit.
It depends on vtk and version 3 of the Insighttoolkit