v0.8.1

You are heavily encouraged to update as this incorporates many new features and bug-fixes.

• Fix a bug when reading non-Gamma TSHS files, now the
  supercell information is correct.

• tbtncSileSiesta now distinguishes between:
  electronic_temperature [K]
  and
  kT [eV]
  where the units are not the same.

• Fixed TBT_DN.nc TBT_UP.nc detection as a Sile

• Added information printout for the TBT.nc files

  sdata siesta.TBT.nc --info

  will print out what information is contained in the file.

• Atoms overhauled with a lot of the utility routines
  inherent to the Geometry object.
  It is now much faster to perform operations on this
  object.

• The FDF sile now allows setting and retrieving variables
  from the fdf file. Hence one may now set specific
  fdf flags via:

   sdata RUN.fdf --set SolutionMethod Transiesta
  

• Changed default output precision for TXT files to .8f.
  Additionally one may use flag --format in sgeom to
  define the precision.

• Shapes have been added. There are now several Shapes
  which may be used to easily find atoms within a given Shape.
  This should in principle allow construction of very complex Shapes
  and easier construction of complex Hamiltonians