Add recommended shebang line to conf.py
Allow to build documentation offline
Remove the _tools folder
Merge pull request #308 from bpindelski/rebased/develop/remove_tools

Remove the _tools folder (rebased onto develop)
Merge pull request #305 from mtbc/add-py-shebang

Add recommended shebang line to conf.py (rebase)
Merge pull request #306 from sbesson/rebased/develop/offline_build

Allow to build documentation offline (rebased onto develop)