doc: Update more docstrings to have one sentence summary as first line. Reviewed miscellaneous, sparse, strings in scripts directory. * scripts/miscellaneous/bzip2.m, scripts/miscellaneous/citation.m, scripts/miscellaneous/compare_versions.m, scripts/miscellaneous/computer.m, scripts/miscellaneous/debug.m, scripts/miscellaneous/dir.m, scripts/miscellaneous/edit.m, scripts/miscellaneous/error_ids.m, scripts/miscellaneous/fileattrib.m, scripts/miscellaneous/fullfile.m, scripts/miscellaneous/genvarname.m, scripts/miscellaneous/gzip.m, scripts/miscellaneous/mkoctfile.m, scripts/miscellaneous/news.m, scripts/miscellaneous/open.m, scripts/miscellaneous/parseparams.m, scripts/miscellaneous/recycle.m, scripts/miscellaneous/run.m, scripts/miscellaneous/swapbytes.m, scripts/miscellaneous/tar.m, scripts/miscellaneous/tmpnam.m, scripts/miscellaneous/unpack.m, scripts/miscellaneous/what.m, scripts/sparse/bicg.m, scripts/sparse/bicgstab.m, scripts/sparse/cgs.m, scripts/sparse/colperm.m, scripts/sparse/eigs.m, scripts/sparse/etreeplot.m, scripts/sparse/gmres.m, scripts/sparse/gplot.m, scripts/sparse/ichol.m, scripts/sparse/ilu.m, scripts/sparse/pcg.m, scripts/sparse/pcr.m, scripts/sparse/qmr.m, scripts/sparse/spaugment.m, scripts/sparse/spconvert.m, scripts/sparse/spdiags.m, scripts/sparse/spfun.m, scripts/sparse/spones.m, scripts/sparse/sprandsym.m, scripts/sparse/spstats.m, scripts/sparse/spy.m, scripts/sparse/svds.m, scripts/sparse/treelayout.m, scripts/sparse/treeplot.m, scripts/strings/base2dec.m, scripts/strings/bin2dec.m, scripts/strings/blanks.m, scripts/strings/cstrcat.m, scripts/strings/deblank.m, scripts/strings/dec2base.m, scripts/strings/dec2bin.m, scripts/strings/dec2hex.m, scripts/strings/findstr.m, scripts/strings/hex2dec.m, scripts/strings/index.m, scripts/strings/isletter.m, scripts/strings/isstrprop.m, scripts/strings/mat2str.m, scripts/strings/ostrsplit.m, scripts/strings/regexptranslate.m, scripts/strings/rindex.m, scripts/strings/str2num.m, scripts/strings/strcat.m, scripts/strings/strchr.m, scripts/strings/strjoin.m, scripts/strings/strjust.m, scripts/strings/strmatch.m, scripts/strings/strsplit.m, scripts/strings/strtok.m, scripts/strings/strtrim.m, scripts/strings/strtrunc.m, scripts/strings/substr.m, scripts/strings/untabify.m, scripts/time/datenum.m: Update more docstrings to have one sentence summary as first line.

--- a/scripts/strings/mat2str.m	Sun May 03 21:52:42 2015 -0700
+++ b/scripts/strings/mat2str.m	Mon May 04 14:22:02 2015 -0700
@@ -19,15 +19,16 @@
 ## -*- texinfo -*-
 ## @deftypefn  {Function File} {@var{s} =} mat2str (@var{x}, @var{n})
 ## @deftypefnx {Function File} {@var{s} =} mat2str (@var{x}, @var{n}, "class")
-## Format real, complex, and logical matrices as strings.  The
-## returned string may be used to reconstruct the original matrix by using
+## Format real, complex, and logical matrices as strings.
+##
+## The returned string may be used to reconstruct the original matrix by using
 ## the @code{eval} function.
 ##
-## The precision of the values is given by @var{n}.  If @var{n} is a
-## scalar then both real and imaginary parts of the matrix are printed
-## to the same precision.  Otherwise @code{@var{n}(1)} defines the
-## precision of the real part and @code{@var{n}(2)} defines the
-## precision of the imaginary part.  The default for @var{n} is 15.
+## The precision of the values is given by @var{n}.  If @var{n} is a scalar
+## then both real and imaginary parts of the matrix are printed to the same
+## precision.  Otherwise @code{@var{n}(1)} defines the precision of the real
+## part and @code{@var{n}(2)} defines the precision of the imaginary part. 
+## The default for @var{n} is 15.
 ##
 ## If the argument @qcode{"class"} is given then the class of @var{x} is
 ## included in the string in such a way that @code{eval} will result in the