move scripts to separate include so we can include them across layouts even if the footer isn't there

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We can't include it in docs.min.js because docs.min.js includes application.js,
application.js depends on bootstrap.js,
and the tooltip portion of bootstrap.js depends on Tether.

So instead, we need to load Tether separately before bootstrap.js

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Now that we don't support IE 8 it's safe to do that.

Move them to footer, and remove duplicate ones.

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1) Update it to v1.0.8
2) Include jekyll-search where it's used only

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Shouldn't really happen, but China for example has blocked Google so this should help.

Added attributes rel and target.

Update Creative Commons link to HTTPS.