doc: Periodic grammarcheck and spellcheck of documentation. * func.txi: Correct two misspellings * cumtrapz.m, dblquad.m, quadgk.m, quadl.m, quadv.m, trapz.m, triplequad.m, cond.m, gmres.m, bzip2.m, compare_versions.m, getappdata.m, unpack.m, ver.m, glpk.m, pkg.m, axis.m, uigetdir.m, uigetfile.m, view.m, prctile.m, quantile.m, unidcdf.m, unidinv.m, isstrprop.m, balance.cc, besselj.cc, cellfun.cc, colamd.cc, dot.cc, eigs.cc, fftw.cc, matrix_type.cc, pinv.cc, qr.cc, quad.cc, quadcc.cc, qz.cc, regexp.cc, schur.cc, time.cc (gmtime), typecast.cc urlwrite.cc bitfcns.cc (bitshift), data.cc (rem, norm, merge) debug.cc (dbstatus), dirfns.cc (glob), file-io.cc (freport), load-path.cc (genpath), load-save.cc (save), mappers.cc (islower, isupper, tolower, toupper) oct-hist.cc (edit_history), ov-fcn-inline.cc (vectorize), ov.cc (subsref), syscalls.cc (stat), variables.cc (whos, clear): Improve docstrings. Removed trailing whitespace characters on line.

--- a/scripts/general/trapz.m
+++ b/scripts/general/trapz.m
@@ -25,7 +25,7 @@
 ## method.
 ## @w{@code{trapz (@var{y})}} computes the integral of @var{y} along the first
 ## non-singleton dimension.  When the argument @var{x} is omitted an
-## equally spaced @var{x} vector with unit spacing (1) is assumed.  
+## equally spaced @var{x} vector with unit spacing (1) is assumed.
 ## @code{trapz (@var{x}, @var{y})} evaluates the integral with respect
 ## to the spacing in @var{x} and the values in @var{y}.  This is useful if
 ## the points in @var{y} have been sampled unevenly.
@@ -45,7 +45,7 @@
 ##   @result{} q = 2.525   # No scaling
 ## q * 0.1
 ##   @result{} q = 0.2525  # Approximation to integral by scaling
-## trapz (x, y) 
+## trapz (x, y)
 ##   @result{} q = 0.2525  # Same result by specifying @var{x}
 ## @end group
 ## @end example