Implement resize

[JohnCoene]

Implement resize, fixes https://github.com/ramnathv/htmlwidgets/issues/161

library(shiny)
library(rhandsontable)

ui <- shinyUI(fluidPage(
  sidebarLayout(
    sidebarPanel(
      checkboxInput("check", "Show Table", FALSE),
      conditionalPanel("input.check === true",
                       rHandsontableOutput("tbl"))
    ),
    mainPanel()
  )
))

server <- function(input, output) {
  output$tbl <- renderRHandsontable({
    rhandsontable(data.frame(col1 = LETTERS[1:10], col2 = 1:10))
  })
}

shinyApp(ui = ui, server = server)

Not sure why it was not implemented, there may be a valid reason I am missing.