doc: Update more docstrings to have one sentence summary as first line. Reviewed specfun, special-matrix, testfun, and time script directories. * scripts/specfun/expint.m, scripts/specfun/isprime.m, scripts/specfun/legendre.m, scripts/specfun/primes.m, scripts/specfun/reallog.m, scripts/specfun/realsqrt.m, scripts/special-matrix/gallery.m, scripts/special-matrix/hadamard.m, scripts/special-matrix/hankel.m, scripts/special-matrix/hilb.m, scripts/special-matrix/invhilb.m, scripts/special-matrix/magic.m, scripts/special-matrix/pascal.m, scripts/special-matrix/rosser.m, scripts/special-matrix/toeplitz.m, scripts/special-matrix/vander.m, scripts/special-matrix/wilkinson.m, scripts/testfun/assert.m, scripts/testfun/demo.m, scripts/testfun/example.m, scripts/testfun/fail.m, scripts/testfun/rundemos.m, scripts/testfun/runtests.m, scripts/testfun/speed.m, scripts/time/asctime.m, scripts/time/calendar.m, scripts/time/clock.m, scripts/time/ctime.m, scripts/time/datenum.m, scripts/time/datestr.m, scripts/time/datevec.m, scripts/time/etime.m, scripts/time/is_leap_year.m, scripts/time/now.m, scripts/time/weekday.m: Update more docstrings to have one sentence summary as first line.

--- a/scripts/time/weekday.m	Sun May 03 15:36:23 2015 -0700
+++ b/scripts/time/weekday.m	Sun May 03 17:00:11 2015 -0700
@@ -20,13 +20,14 @@
 ## @deftypefn  {Function File} {[@var{n}, @var{s}] =} weekday (@var{d})
 ## @deftypefnx {Function File} {[@var{n}, @var{s}] =} weekday (@var{d}, @var{format})
 ## Return the day of the week as a number in @var{n} and as a string in @var{s}.
+##
 ## The days of the week are numbered 1--7 with the first day being Sunday.
 ##
 ## @var{d} is a serial date number or a date string.
 ##
-## If the string @var{format} is not present or is equal to @qcode{"short"} then
-## @var{s} will contain the abbreviated name of the weekday.  If @var{format}
-## is @qcode{"long"} then @var{s} will contain the full name.
+## If the string @var{format} is not present or is equal to @qcode{"short"}
+## then @var{s} will contain the abbreviated name of the weekday.  If
+## @var{format} is @qcode{"long"} then @var{s} will contain the full name.
 ##
 ## Table of return values based on @var{format}:
 ##