Add an old blog post: 750 words

Taken from one of my other blogs.
Add an old blog post: On Living in Japan

Taken from one of my other blogs.
Add an old blog post on Git SHA-1 hashes

Taken from one of my other blogs.
Fix linked futon images for On Living in Japan
Replace YouTube Flash player with HTML5 player
Temporarily hide new Jekyll blog post

I'm starting to merge content from all of my other blogs with this one,
and in context the new Jekyll blog post doesn't make a lot of sense. I
need to edit it a bit before I re-publish it.
Standardize date formats in YAML front matter