literalize.css: Style rmarkdown with <!-- rmarkdown v1 -->
hooks: Implement knit_expand based templates.

- Prepare hooking mechanism for extension to other formats
  using a pattern list.
literalize.js: Align markdown_v1 full markdown chunk output.

- Prevent staggered output when script isn't included and
  make markdown more consistent with rmarkdown v2 output.
dye.R: Provide method to include style scripts.

- Emits style data 'asis'