DataTables 1.10.2

Shiny gallery examples have been updated in the repo but not on the website yet (should be there after shiny 0.10.2 is released): https://github.com/rstudio/shiny-examples/commit/6f2a5618d12b0ea62437aa88188ac5531bc7dc35

There are more examples to work on to explore the new features of DT 1.10.

To test this PR, `devtools::install_github('yihui/shiny@feature/datatables1.10')`
Hi @jcheng5, @wch was wondering if you prefer this to be `warning()` or `message()`. Neither of us has a strong preference here, but we want to ask you just in case.