fix arg(...) with a rvalue
source code cleaning
transform_accumulate algorithm
rename falcon::algorithm::... to falcon::...
fn::index -> fn::idx ; fn::pointer_to_membre -> fn::ptr_to_mem
c++11 or later only
fixes fn::{c[r]{begin,end} and fn::{rbegin,rend} used std::reverse_iterator if the reverse iterator member function isn't found
c++11 or later only
various improvement and fix tests