fixes #90: textOuput() can be put in any tag now

for the example, we use <span>, which is allowed in <h3>
Fix issue #381: sendOutputHiddenState is called too many times
Don't show broken image when plot is empty

Repro case:

shiny::runApp(list(
  ui=basicPage(plotOutput('foo')),
  server=function(input, output, session) {
    output$foo <- renderPlot({})
  }
))
Merge pull request #383 from jcheng5/bugfix/broken-image

Don't show broken image when plot is empty
just to avoid the spurious warning in R CMD check "doRenderTags: no visible binding for global variable 'htmlResult'"
Fix URL for slider number format details

Fixes issue #384
Merge pull request #363 from yihui/text-output-container

fixes #90: textOuput() can be put in any tag now
Staticdocs index info
Udpate to jQuery 1.11.0

This makes the following JS console message (as noted in #271) go away:
event.returnValue is deprecated. Please use the standard event.preventDefault() instead.
Remove console logging code
Add comments about debouncing
Merge branch 'bugfix/381-sendOutputHiddenState'
Minor doc tweaks

- Combine sliderInput and animationOptions topics
- Provide better staticdoc index descriptions

Sorry for the big diff, that's due to using a newer version of roxygen.
Add check for staticdocs index correctness
Suppress staticdocs test when run on a built package