added code to find ebook-convert
Merge pull request #487 from kbrock/makeebook_fixes

added code to find ebook-convert
[ja] Apply b4854ff8dc42db658df66ecdd8fe2162a73ebdb5

Merge pull request #435 from GArik/EN
https://github.com/progit/progit/commit/b4854ff8dc42db658df66ecdd8fe2162a73ebdb5
Merge pull request #488 from harupong/ja-chapter7

[ja] Apply b4854ff8dc42db658df66ecdd8fe2162a73ebdb5
Merge branch 'progit/master'