Give credit to authors

[guitorri]

Original authors of the help files:

./characters.html:<meta name="Author" content="Michael Margraf">
./index.html:<meta name="Author" content="Michael Margraf">
./internal.html:<meta name="Author" content="Michael Margraf">
./matching.html:<meta name="Author" content="Michael Margraf">
./mathfunc.html:	<META NAME="AUTHOR" CONTENT="Michael Margraf">
./octave.html:<meta name="Author" content="Michael Margraf">
./programs.html:<meta name="Author" content="Michael Margraf">
./short.html:<meta name="Author" content="Michael Margraf">
./start.html:<meta name="Author" content="Michael Margraf">
./start_digi.html:<meta name="Author" content="Michael Margraf">
./start_opt.html:<meta name="Author" content="Public domain">
./subcircuit.html:<meta name="Author" content="Michael Margraf">