bug correction to dgGroupOfInterfaces in 3d  + check for not defined boundaries + remove left/right interface on dgGroupOfFaces

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Added Navier Stokes & 2 test cases in DG
Added binary restart capabilities in DG
Added mesh renumbering option (-renumber)@

though. doc interface is present but no doc is generated

Multiscale Laplace works 

- more work on slepc integration

- moved GUI to FlGui + added experimental QGui to test Qt

- fixed most MSVC and gcc compiler warnings

- converted some remaining tabs to whitespace (that's why the patch is
  so large; please try to remember to indent with 2 spaces and not
  tabs when you commit stuff to CVS)

- merged modified patch from Konstantinos Poulios to allow saving
  physical/partition as element tags in mesh formats that don't
  support them natively

Added a sort of the eigenvalues and print functions

tests with jf

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

HAVE_XXX defines.

This fixes three longstanding problems:

- the API was hard to use because some headers had HAVE_XXX ifdefs, so
  that cient codes had to know how the lib was compiled to compile
  themselves

- we had to do make clean after each ./configure, which erased too
  much (e.g. most of contrib)

- make depend could include unwanted stuff since it redefined FLAGS

- fix bb computation to avoid model jumping around when adding points in z=0 plane
- pass interpol matrices as ref