20040905 -> (empty string)
3.0c-r1 -> 0c-r1
.TP
\fBreplace_version_sepaator\fR <search> <replacement> [subject]
\fBreplace_version_separator\fR <search> <replacement> [subject]
Replace the $1th separator with $2 in $3 (defaults to $PV if $3 is not
supplied). If there are fewer than $1 separators, don't change anything.
1 '_' 1.2.3 -> 1_2.3