-Efecto zoom-in & zoom-out.

Signed-off-by: Ivan Marmolejo <ivanm@librerialeo.com.mx>
Merge branch 'master' of https://github.com/librerialeo/ebooks

Conflicts:
	index.php
	js/subrayar.js

Signed-off-by: Ivan Marmolejo <ivanm@librerialeo.com.mx>