title: Change size of actionButton and its label
body: <p>How can I make an <code>actionButton</code> and its label smaller, but still centered in the button icon?  I have been able to accomplish making both the button and the text smaller, but the result is a small button with small text that isn't centered in the button.  I think I'm probably approaching this incorrectly.  Here is an example where the button/text gets smaller but the result is a button with the text not centered.</p>
  
  <pre><code>library(shiny)
  
  shinyApp(
      shinyUI(fluidPage(
          inputPanel(
              ## Original
              actionButton('button', 'Hi'),
  
              ## Text is smaller
              gsub('Hi', '&lt;font size="1"&gt;Hi&lt;/font&gt;',
                   actionButton('button1', 'Hi')),
  
              ## Text is smaller and button is smaller, but text is outside of button
              gsub('Hi', '&lt;font size="1" align="center"&gt;Hi&lt;/font&gt;',
                   actionButton('button2', 'Hi', style='height:20px'))
              )
      )),
      shinyServer(function(input,output){})
  )
  </code></pre>