Make options a gathered file

Various modules used options object (in_place_, vector_ etc) and everythign was lumped into a nonsensical file. This pacth fix this by : 

 - removing useless options and amending functions usign them
 - make the nt2/options.hpp be auto-gathered at cmake-time
 - fix a couple of functions that used options incorrectly

This is roughly related to #765 even if it doesn't fix the in_place_ issue itself.