Update compare_cmaps to print details about cmap differences.
Update compare_cmaps to print details about cmap differences.

Details will list characters by block, and show for removed
characters the remaining locations of those characters.

moyogo/nototools,googlei18n/nototools,googlefonts/nototools,anthrotype/nototools,googlefonts/nototools,anthrotype/nototools,googlefonts/nototools,dougfelt/nototools,googlei18n/nototools,googlefonts/nototools,moyogo/nototools,moyogo/nototools,googlei18n/nototools,anthrotype/nototools,dougfelt/nototools,dougfelt/nototools,googlefonts/nototools