Testing the license in python and jinja files.

* testing `.py` and `.html` for license.
* empty files are ignored (use case: `__init__.py`)
* new set of codes starting with `I` (compatible with `PEP8_IGNORE`)
* fuzzy test to recognize the GNU GPLv2 (or GNU GPLv3)

### Example
**inveniosoftware/invenio@9b7e4b9**
```
modules/bibclassify/lib/bibclassify_webinterface.py: 17: I101 copyright is missing
modules/bibsword/lib/bibsword_webinterface.py: 0: I101 copyright is missing
modules/bibfield/lib/functions/get_doi.py: 15: I101 copyright is missing
modules/miscutil/lib/__init__.py: 0: I101 copyright is missing
modules/miscutil/lib/plotextractor_output_utils.py: 10: I101 copyright is missing
modules/miscutil/lib/redisutils.py: 0: I101 copyright is missing
modules/miscutil/lib/logicutils.py: 34: I101 copyright is missing
modules/miscutil/lib/pep8.py: 24: I101 copyright is missing
modules/bibauthorid/lib/bibauthorid_bib_matrix.py: 0: I101 copyright is missing
modules/webcomment/lib/webcomment_washer.py: 0: I101 copyright is missing
```

**jirikuncar/invenio@db29742**
```
testsuite/test_apps/last/templates/page.html: 0: I101 copyright is missing
testsuite/test_apps/first/templates/page.html: 0: I101 copyright is missing
base/templates/admin_base.html: 0: I101 copyright is missing
modules/messages/templates/messages/email_alert.html: 1: I101 copyright is missing
modules/deposit/templates/deposit/run_group_end.html: 0: I101 copyright is missing
modules/deposit/templates/deposit/run_field.html: 0: I101 copyright is missing
modules/deposit/templates/deposit/run_field_subform.html: 0: I101 copyright is missing
modules/deposit/templates/deposit/widget_plupload.html: 0: I101 copyright is missing
modules/deposit/templates/deposit/run_group_start.html: 0: I101 copyright is missing
modules/deposit/templates/deposit/run_field_label.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/index.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_layout.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_index.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_approval_widget.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/workflow_details.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_bibmatch_widget.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/layout_workflow_details.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/entry_details.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_maintable.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/workflows.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_utils.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/layout.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/hp_details.html: 0: I101 copyright is missing
modules/workflows/templates/workflows/utils.html: 0: I101 copyright is missing
modules/communities/templates/communities/new_upload_email.html: 0: I101 copyright is missing
modules/documentation/templates/documentation/index.html: 0: I101 copyright is missing
modules/accounts/templates/accounts/widget_base.html: 0: I101 copyright is missing
```