seq(1): Consistently include 'last' for non-integers

seq(1): Consistently include 'last' for non-integers

The source of error is a rounded increment being too large and thus the loop
steps slightly past 'last'.  Perform a final comparison using the formatted
string values (truncated precision) to determine if we still need to print
the 'last' value.

PR:		217149
Submitted by:	Fernando Apesteguía <fernando.apesteguia AT gmail.com>,
		Yuri Pankov <yuripv AT icloud.com> (earlier version)
Reported by:	Martijn Dekker <mcdutchie AT hotmail.com>
Sponsored by:	Dell EMC Isilon