Adding basic gulp interface.

  * Added some general functions to make wrapping functionals easier and
    more systematic.
  * lead to some bug corrections in dftcrystal.
  * current gulp interface tested for some things but has not yet been
    runned.
added run test to gulp. works.
forgot test file
some bug corrections to gulp
Moving crystal iterators to separate subpackage
Merge branch 'next/master' of ssh://github.com/mdavezac/LaDa into next/master
Forgot iterator file
Adding basic gulp interface.

  * Added some general functions to make wrapping functionals easier and
    more systematic.
  * lead to some bug corrections in dftcrystal.
  * current gulp interface tested for some things but has not yet been
    runned.
added run test to gulp. works.
forgot test file
some bug corrections to gulp
Merge branch 'next/gulp' of ssh://github.com/mdavezac/LaDa into next/gulp
adding extra extract.structure tests in gulp
finished adding extra test
Adding springs and species to GULP
Changed lada to pylada
Merge remote-tracking branch 'github/next/gulp' into next/master
Changing gulp to pylada