doc: Add @nospell macro around proper names in documentation. * aspell-octave.en.pws: Remove proper names from Octave's custom dictionary. * doc/interpreter/audio.txi, doc/interpreter/diagperm.txi, doc/interpreter/diffeq.txi, doc/interpreter/emacs.txi, doc/interpreter/func.txi, doc/interpreter/geometry.txi, doc/interpreter/intro.txi, doc/interpreter/linalg.txi, doc/interpreter/numbers.txi, doc/interpreter/preface.txi, doc/interpreter/quad.txi, doc/interpreter/sparse.txi, libinterp/corefcn/colloc.cc, libinterp/corefcn/ellipj.cc, libinterp/corefcn/gammainc.cc, libinterp/corefcn/hess.cc, libinterp/corefcn/quadcc.cc, libinterp/corefcn/rand.cc, libinterp/corefcn/sqrtm.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/colamd.cc, libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/symrcm.cc, scripts/general/quadgk.m, scripts/general/quadl.m, scripts/linear-algebra/commutation_matrix.m, scripts/linear-algebra/condest.m, scripts/linear-algebra/duplication_matrix.m, scripts/linear-algebra/expm.m, scripts/linear-algebra/housh.m, scripts/linear-algebra/krylov.m, scripts/linear-algebra/onenormest.m, scripts/linear-algebra/qzhess.m, scripts/optimization/fminsearch.m, scripts/optimization/glpk.m, scripts/signal/arch_fit.m, scripts/signal/bartlett.m, scripts/signal/blackman.m, scripts/signal/diffpara.m, scripts/signal/durbinlevinson.m, scripts/signal/hamming.m, scripts/signal/hanning.m, scripts/sparse/eigs.m, scripts/sparse/pcg.m, scripts/sparse/pcr.m, scripts/specfun/ellipke.m, scripts/special-matrix/gallery.m, scripts/special-matrix/invhilb.m, scripts/statistics/base/quantile.m, scripts/statistics/tests/kruskal_wallis_test.m, scripts/statistics/tests/manova.m, scripts/statistics/tests/mcnemar_test.m: Add @nospell macro around proper names in documentation.

--- a/libinterp/corefcn/sqrtm.cc	Thu Aug 21 18:49:47 2014 +0100
+++ b/libinterp/corefcn/sqrtm.cc	Thu Aug 21 15:57:18 2014 -0700
@@ -206,7 +206,7 @@
 @deftypefnx {Built-in Function} {[@var{s}, @var{error_estimate}] =} sqrtm (@var{A})\n\
 Compute the matrix square root of the square matrix @var{A}.\n\
 \n\
-Ref: N.J. Higham.  @cite{A New sqrtm for @sc{matlab}}.  Numerical\n\
+Ref: @nospell{N.J. Higham}.  @cite{A New sqrtm for @sc{matlab}}.  Numerical\n\
 Analysis Report No. 336, Manchester @nospell{Centre} for Computational\n\
 Mathematics, Manchester, England, January 1999.\n\
 @seealso{expm, logm}\n\