next: set if we need to evolve or not; also move logic to appropriate pos
set the value `needevolve` and also move the logic to find aspiringchildren
to appropriate position i.e before we suggest user to use other flags like
--merge.
next: move some code to prepare for `next --evolve` by default
Moved some values before the block where we suggest the user to use
--merge flag. As we would need these values to find if we need to evolve
or not before we can suggest user to use `--merge` flag.
We will suggest user to use `--merge` flag only when we don't need to
evolve. Because currently we don't support both --evolve(going to be True
by default) and --merge at the same time.