Pagell -> Pagella (typo fix)

In this commit I fix a typo.
And I also take the chance to ask where the font is defined.
I expected a \usepackage{tgpagella} somewhere in cls or tex files.

Author: hochB

copyrightpage.tex

@@ -8,7 +8,7 @@
 form by any electronic or mechanical means (including photocopying,
 recording or information storage and retrieval)
 without permission in writing from the publisher.\\[0.2in]
-This book was set in \TeX\ Gyre Pagell by the authors in \LaTeX.\\
+This book was set in \TeX\ Gyre Pagella by the authors in \LaTeX.\\
 Printed and bound in the United States of America.\\[0.2in]
 Library of Congress Cataloging-in-Publication Data is available.\\[0.2in]
 ISBN: \\[0.2in]