[MSG OK] better error handling between server-side graph generation and the error messages shown on client-side

Rename our server-side "graphExplorer" app to "graph", in order to prevent confusion with client-side tina-based graphExplorer from static/lib

(recuperation de la nouvelle façon d'envoyer des messages + statut HTTP pour utilisation côté graphExplorer)

[MERGE OK] added small readme and removed old symlinks to tinawebJS in gargantext_lib (not necessary anymore)

git-subtree-dir: static/lib/graphExplorer
git-subtree-mainline: 3bfb7073
git-subtree-split: d256049a

integrate recent post-refactoring gargantext changes to *extras_explorerjs* (new paths for corpora, intersection, node deletion and static imgs)

add debug traces to each function, remove trailing spaces in scripts, add initialization call graph schema

Now Graph is not computed each time: just getting the data from the
node.

	modifié :         gargantext/views/api/urls.py
	modifié :         graphExplorer/cooccurrences.py
	modifié :         graphExplorer/graph.py
	modifié :         graphExplorer/rest.py
	modifié :         graphExplorer/urls.py
	modifié :         graphExplorer/views.py
	modifié :         static/lib/graphExplorer/settings_explorerjs.js
	modifié :         templates/graphExplorer/explorer.html
	nouveau fichier : templates/pages/corpora/myGraphs.html