make -column lists pretty again;

specifically, rewrite them to permit some markup in the column headers,
and use "Ta" instead of literal tabs; mandoc does not currently match groff
100%, but a mandoc fix may be some time off, and we've gone enough releases
with poorly formatting column lists.
in some cases i have rewritten the lists as -tag, where -column made
little sense.

src/lib/libc/stdlib/strtol.3

@@ -29,9 +29,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: strtol.3,v 1.20 2011/08/30 12:25:09 jmc Exp $
+.\"	$OpenBSD: strtol.3,v 1.21 2011/09/03 22:59:07 jmc Exp $
 .\"
-.Dd $Mdocdate: August 30 2011 $
+.Dd $Mdocdate: September 3 2011 $
 .Dt STRTOL 3
 .Os
 .Sh NAME
@@ -164,7 +164,7 @@ If overflow or underflow occurs,
 is set to
 .Er ERANGE
 and the function return value is as follows:
-.Bl -column "strtoimax" "overflow" "underflow" -offset indent
+.Bl -column "strtoimaxXX" "INTMAX_MIN" "INTMAX_MAX" -offset indent
 .It Sy Function Ta Sy underflow Ta Sy overflow
 .It Fn strtol Ta Dv LONG_MIN Ta Dv LONG_MAX
 .It Fn strtoll Ta Dv LLONG_MIN Ta Dv LLONG_MAX