[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

fix bulk_insert_ifnotexists occasional bugs with better term normalization sequence and reduce frequency of integrate step (reduce DB effort but use slightly more RAM)

[WIP] old specificity metric transformed into 2 better metrics: specclusion and genclusion based on conditional probability