[Python-ideas] add a time decorator to timeit.py

I think that a time decorator will be a useful addition to the sandard library, as i find the current way of measuring execution time a bit tedious: timeit.timeit("fun_to_time(a, b)", setup="from __main__ import a, b", number=1) compared to: @timef def fun_to_time(a, b): ... or timef(print)("Hello world!"). I already made a basic implementation of it, and it's working well.