templatefuncs: do not stringify result of if*() expression
Returning a generator means that the result is a byte string. I can't find
any reason to make the "if" condition lazy since it is evaluated anyway
when {if()} has to be evaluated. So let's simply make if*() return an input
expression unmodified.
Ancestors of 5
4 2 0
Ancestors of 6 and 5
3 4 2 1 0
Ancestors of 5 and 4
4 2 0
Ancestors of 7, stop at 6
6
Ancestors of 7, including revs
7 6 5 3 4 2 1 0
Ancestors of 7, 5 and 3, including revs
7 5 3 6 4 2 1 0
Descendants of 5
7 8
Descendants of 5 and 3
6 7 8
Descendants of 5 and 4
5 7 8