maint: Remove special cases of old version control keywords in code base. * common_size.m, cumtrapz.m, interp1.m, polyarea.m, trapz.m, inpolygon.m, summer.m, javamem.m, duplication_matrix.m, subspace.m, starting_stepsize.m, text.m, errorbar.m, loglogerr.m, peaks.m, __errplot__.m, semilogxerr.m, semilogyerr.m, stemleaf.m, streamtube.m, __pltopt__.m, printd.m, pchip.m, arch_fit.m, arch_rnd.m, arch_test.m, arma_rnd.m, autoreg_matrix.m, bartlett.m, blackman.m, diffpara.m, durbinlevinson.m, fractdiff.m, hamming.m, hanning.m, hurst.m, ifftshift.m, periodogram.m, rectangle_lw.m, rectangle_sw.m, triangle_lw.m, triangle_sw.m, sinetone.m, sinewave.m, spectral_adf.m, spectral_xdf.m, spencer.m, stft.m, synthesis.m, yulewalker.m, bicg.m, bicgstab.m, cgs.m, gmres.m, pcr.m, sprand.m, tfqmr.m, betaincinv.m, betaln.m, gammaincinv.m, hadamard.m, center.m, cov.m, discrete_inv.m, discrete_pdf.m, discrete_rnd.m, empirical_cdf.m, empirical_inv.m, empirical_pdf.m, empirical_rnd.m, iqr.m, kendall.m, mean.m, meansq.m, moment.m, prctile.m, quantile.m, range.m, run_count.m, spearman.m, statistics.m, var.m, zscore.m, datenum.m, datevec.m: Remove special cases of old version control keywords in code base.

--- a/scripts/polynomial/pchip.m	Tue Jan 21 13:20:01 2020 -0800
+++ b/scripts/polynomial/pchip.m	Tue Jan 21 14:04:31 2020 -0800
@@ -64,10 +64,8 @@
 ## @seealso{spline, ppval, mkpp, unmkpp}
 ## @end deftypefn
 
-## Author:  Kai Habel <kai.habel@gmx.de>
-## Date: 9. mar 2001
-##
-## S_k = a_k + b_k*x + c_k*x^2 + d_k*x^3; (spline polynom)
+## Algorithm:
+## S_k = a_k + b_k*x + c_k*x^2 + d_k*x^3; (spline polynomial)
 ##
 ## 4 conditions:
 ## S_k(x_k) = y_k;