Merge pull request #14 from GkAntonius/master

Reorganized abipy.htc.inputfile
 Start to move flow factory functions to pymatgen.
 Import upstream (Gabriel's modifications)
 There was a problem with htc/tests/test_inputfile.py (Added to the branch)
Merge branch 'master' of https://github.com/gmatteo/abipy
 This version passes the tests with my pymatgen branch: a5e6bb1ec7d3005fcad25a82f1fff6e0009ed2e6
 Preliminary support for Optic (quick-and-dirty but it seems to work)
 Easier API for the definition of OptictTasks
 Polymorphic interface for OpticsTask that accepts FileNode objects
 Add new script cif2spg.py
 Add script for the computation of the deltafactor.
 Remove support for Workflows in abirun.py
 Add doc to run_deltafactor.py
 Minor changes.
 Fix typo
 Add new script run_phonons for Phonon calculations.
 Add doc in the new scripts.
 Replace TaskManager.from_file with TaskManager.from_user_config
 Modify syntax in abirun.py (rapidfire dirname --> dirname rapidfire)
 New option "inspect" for inspecting the calculation of the Task.