[web] Optimized images on books.

web/content/books/BMB-2-Cover.png

web/content/books/BMB-3-Cover.png

web/content/books/Computation-Hydrology-I-Cover.png

web/content/books/bmb-4.png

web/content/books/computational-geotechnics-i.png

web/content/books/computational-hydrology-ii.png

web/content/books/geoenergy-modeling-i.png

web/content/books/geoenergy-modeling-ii.png

web/content/books/geoenergy-modeling-iii.png

web/content/books/models-of-thermochemical-heat-storage.png