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/sparse/spdiags.m	Sun May 03 21:52:42 2015 -0700
+++ b/scripts/sparse/spdiags.m	Mon May 04 14:22:02 2015 -0700
@@ -22,21 +22,22 @@
 ## @deftypefnx {Function File} {@var{B} =} spdiags (@var{A}, @var{d})
 ## @deftypefnx {Function File} {@var{A} =} spdiags (@var{v}, @var{d}, @var{A})
 ## @deftypefnx {Function File} {@var{A} =} spdiags (@var{v}, @var{d}, @var{m}, @var{n})
-## A generalization of the function @code{diag}.  Called with a single
-## input argument, the nonzero diagonals @var{d} of @var{A} are extracted.
-## With two arguments the diagonals to extract are given by the vector
-## @var{d}.
+## A generalization of the function @code{diag}.
+##
+## Called with a single input argument, the nonzero diagonals @var{d} of
+## @var{A} are extracted.
+##
+## With two arguments the diagonals to extract are given by the vector @var{d}.
 ##
-## The other two forms of @code{spdiags} modify the input matrix by
-## replacing the diagonals.  They use the columns of @var{v} to replace
-## the diagonals represented by the vector @var{d}.  If the sparse matrix
-## @var{A} is defined then the diagonals of this matrix are replaced.
-## Otherwise a matrix of @var{m} by @var{n} is created with the
-## diagonals given by the columns of @var{v}.
+## The other two forms of @code{spdiags} modify the input matrix by replacing
+## the diagonals.  They use the columns of @var{v} to replace the diagonals
+## represented by the vector @var{d}.  If the sparse matrix @var{A} is
+## defined then the diagonals of this matrix are replaced.  Otherwise a
+## matrix of @var{m} by @var{n} is created with the diagonals given by the
+## columns of @var{v}.
 ##
-## Negative values of @var{d} represent diagonals below the main
-## diagonal, and positive values of @var{d} diagonals above the main
-## diagonal.
+## Negative values of @var{d} represent diagonals below the main diagonal, and
+## positive values of @var{d} diagonals above the main diagonal.
 ##
 ## For example:
 ##