add loading animation.

[donotos]

feel free to put that one in the bottom of your backlog, because it is really something that's akin to fine tuning.

with some very high rez pannels, thoses take some time to load, and during that time it is still the previous page that is displayed on the screen, even worse, you can still click on it and advance the pages and the displayed page will still be the same, which can give the impression that mangapie or your network got problems...

can you add some sort of loading animation when the page is loading and prevent the user to advance pages further until the page is loaded?

[pierobot]

Will be included alongside https://github.com/pierobot/mangapie/issues/157