Merge pull request #1003 from Frenzie/master

Kobo Aura H2O detection: slight code refactoring.
fix #929 by validating image magic number
Merge pull request #1005 from chrox/fix_929

fix #929 by validating image magic number
Merge pull request #1006 from Frenzie/master

Kobo Aura H2O: fix bezel.