Copy IPython-configurable with the same hierarchy
copy IPython application and loader
nbconvert is now configurable app
working config
add extract_figures configurable.

remove old useless configurable
Allow to build a converter without input file
fix tests
missing comma
fix after exclude
downgrade docutils in requiremetns.txt
regenerate test case with newest version of ipython
skip html on travis
starting templates
less newline
null template
handle unicode output
onlynewline
inheritance example and doc
add any-cell block
deal with worksheets