Several updates: TES, new Legend const., ntuples path, bug fix in sample.py...

About the bug fix in sample.py (around line 620): fix case where merged_record was called on an array of tuple instead of an array of float in draw_array_helper.

In general it is better to keep the master branch clean here. If you need to make temporary changes to perform tests then you can do that on other branches. Otherwise the master branch gets cluttered with a lot of commented out temporary dead code.