kcc: better epub support

Hi,
I noticed on my PocketBook 912 (one of the few 9.7" eink readers still on the market) that the epub files generated by kcc displayed fine (no image distortion whatsoever), except for one tiny margin of a few pixels.

Thus I generated an epub using calibre, and I saw from the structure that they used two tiny stylesheets. Why two? I don't know, but since Calibre epubs are read on many many readers, I preferred to keep that structure.
I modified kcc to use these stylesheets, and it works GREAT on my pocketbook 912, using the DXG profile and gamma=2.2.

By the way, for testing purposes, I saw that amazon distributes a "Kindle Previewer" which lets you preview the output on all kindles, including fire and fire HD (google it).

Cheers,
Fred