Squeezed #if defined(HAVE_KBIPACK) preprocessor instructions only around
those parts where kbipack is really needed. It seems some homology fun
can be done without it when using coreduction algorithm.

- display all control points in GUI for gmsh curves
- uniformize Fl_Value::step() values in GUI

method to kbipack.

* hack for more stupid binary stl file headers

Begun writing ChainComplex class. Will have own file some day.

Also added an example file celldriver.cpp and transformer.geo
in /utils/misc

They construct a cell complex of a finite elemement mesh of a model,
and are able to reduce and coreduce it in order to compute model's
homology groups.

Also added contrib/kbipack to by Saku Suuriniemi for future use to
compute Smith normal forms of the boundary operator matrices of the
reduced cell complex.

Modified Makefiles and configure.in accordingly.

- simplified background drawing (+added option to use jpeg/png image)
- better default clipping planes

  kernel-specific information
- better documentation of lists returned by extrusions

tests with jf

added simple Helhmoltz solver + demo finite element plugin

Removed GSL dependency. Gmsh now uses blas and lapack for linear algebra
stuff.