cloudconnector: onedrive replaces skydrive

* OneDrive is the new name of the service previously known as SkyDrive:
  https://github.com/mk-fg/python-onedrive/commit/a69252e

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
installation: Pillow instead of PIL

* Deleting PIL since Pillow replaces it and PIL doesn't resolve anymore
  on PyPI. NB: Ubuntu and Debian python-imaging package uses Pillow.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
travis: extra requirements to tests

* Adding -img and -extras to the installation process, so if anything
  break, we might get notified.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
installation: Flask-Assets 0.9 and Jinja2 2.7.2

* Removing webassets from the requirements as its a direct dependency of
  Flask-Assets.

* Upgrading Jinja2 to 2.7.2.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
assets: working combined assets

* Using STATIC_MAP to distinguish between modules and external
  resources.

* Adds STATIC_URL_PREFIX for prefixing all the static files in
  production mode. Useful if you have a dedicated host for static files.

* Relying on ASSETS_DEBUG for webassets debug mode.

* Fixing the documentation for sphinx.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
base: documentation fixes

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
docs: invenio.ext.assets added

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>