doc: Correct off-by-1 spacings in all .cc docstrings * __makeinfo__.m: Only remove space at beginning of new line for docstrings from scripts/ directory where this is the convention. * besselj.cc, betainc.cc, cellfun.cc, dot.cc, fftw.cc, filter.cc, find.cc, gammainc.cc, gcd.cc, givens.cc, hex2num.cc, kron.cc, lu.cc, max.cc, qr.cc, quadcc.cc, qz.cc, regexp.cc, strfind.cc, sub2ind.cc, syl.cc, time.cc, typecast.cc, urlwrite.cc, data.cc, dirfns.cc, file-io.cc, help.cc, load-path.cc, mappers.cc, oct-parse.yy, ov-base.cc, ov-cell.cc, ov-struct.cc, ov.cc, pr-output.cc, pt-mat.cc, strfns.cc, syscalls.cc, variables.cc: Improve appearance of docstring spacing of @example code.

--- a/src/help.cc
+++ b/src/help.cc
@@ -587,7 +587,7 @@
 @example\n\
 @group\n\
 global @var{x};\n\
-if isempty (@var{x})\n\
+if (isempty (@var{x}))\n\
   x = 1;\n\
 endif\n\
 @end group\n\