Make it a bit easier to work on website

`python make website` gives the commands you can use, but also
emmediately clones the website repository

`python make images` clones the images repository so that the
website builder can build the gallery.
FIX: Fix test
WIP: Add JFA example
FIX: Filename
FIX: Fix viewport [ci skip]
FIX: Multiple fixes
FIX: Fix organization [ci skip]
FIX: Fix problems [ci skip]
FIX: Cleaner [ci skip]
FIX: Fix examples
FIX: Fix Framebuffer and examples
FIX: abspath
FIX: Py3k
Merge pull request #313 from Eric89GXL/ipynb-fix

FIX: Fix test
FIX: Fix coverage
FIX: Fix with call [ci skip]
Merge pull request #330 from Eric89GXL/jfa

ENH: Example of translating existing project
Merge pull request #312 from almarklein/easier-make-website

Make it a bit easier to work on website