修复lexed属性未被赋值的bug

Merge branch 'master' of github.com:GitbookIO/gitbook

Conflicts:
	theme/assets/app.js
	theme/assets/print.css

更新说明文档

fix sharing buttons float

Bump version to 0.7.0

Bump version to 0.6.3

Bump version to 0.6.2

Bump version to 0.6.1

Bump version to 0.6.0

Bump version to 0.5.6