update mupdf and k2pdfopt to the latest version
update koreader-base
Merge pull request #283 from chrox/master

update mupdf and k2pdfopt to the latest version
update koreader-base
Merge pull request #284 from chrox/master

update koreader-base
update koreader-base
Merge pull request #286 from chrox/master

update mupdf.patch in koreader-base