Output formats provided by tablib are not available when using python3

[wmj]

Related: #8

[wmj]

Fixed multiple encoding issues in order to being able to use tablib in python3

csb2format: * Information mode is shown in summary * Body moved to module utils.cmd in order to make tests easier to develop * tests added

csb43: * transaction:reference2 should allow punctuation characters (see ticket #10) * Use latin1 as default record encoding * showInfo refactored as a csb43.File method * as_dict: string fields as returned as unicode strings * Tests added

conversion: * conversion to other formats uses unicode fields * tablib backend enabled in python3 (see ticket #9)

global changes: * The project is now by default python3. * IS_PY3 replaced by IS_PY2. * Do not ignore system exceptions. * Python 2/3 compatibility utils moved to module utils.compat. * make clean * added target to tox: flake8 * updated i18n: es-ES * script to propagate version * updated sphinx doc * some flake8 fixes

→ <<cset d10401363433>>