Add absolutePanel and fixedPanel (and jquery-ui)

jQueryUI is needed for draggable functionality.
Smarter cursor choosing for absolutePanel
Minor doc tweak
Merge remote-tracking branch 'origin/master' into feature/absolute-panel

Conflicts:
	DESCRIPTION
Unify jqueryui copies
fixes #90: textOuput() can be put in any tag now

for the example, we use <span>, which is allowed in <h3>
Missing semicolon
Add new object for handling singletons
Fixes for jshint
Export renderHtml function and un-export singletons object
Merge pull request #376 from wch/singleton

Add exports.renderHtml function
use values instead of names for radioButtons due to #340

the problem was revealed from #377
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
Remove caTools dependency
Merge pull request #363 from yihui/text-output-container

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