[IMP] massive optimization of the graph view code: more efficient access to values and smarter code to avoid reading uselessly many cells (graph view in web_graph)
[MERGE] merge from trunk
[FIX] correctly determines when there is no data to read in graph view (instead of the good old crash) (addon web_graph)
[IMP] performance improvement: write a custom isEqual function to use instead of _.isEqual to make the code faster in graph view (isEqual was determined guilty of being slow by profiling on a large view) (addon web_graph)
[MERGE] merge from trunk
[MERGE] this commit contains a fix for a crash when the graph view does not have any data (wrong check for 0 data) and a quite good optimization of the javascript code in graph view when loading large tables. (addon graph view)