Extract HTML functionality to htmltools library
Fix broken client-side HTML dependency rendering
Add S3 method for turning render function into tags
Remove obsolete entry from staticdocs index
Adapt to htmltools 0.2.1 API
Dependency fixes

1) Give bootstrap deps a path so they can be used in static docs
2) Resolve dependencies before rendering page (whoops)
Update htmltools version
Make S3 method consistent with base
Restore HTML generating functions

These functions were temporarily ripped out of Shiny and moved
to the htmltools package. We've discovered that it's safe to
keep including them in shiny; as long as the functions in shiny
and the functions in htmltools are identical, the user won't
receive a conflict warning.
Merge branch 'htmltools-refactor'
Bump version to 0.9.1.9009