title: Unicode characters not recognised by LaTex in RMarkdown Pander table
body: <p>I am trying to get some greek characters into the rownames of a table in rmarkdown knitting to pdf. I am using knitr, pander and MacTex. It seems like pander accepts some unicode characters but not others. When i use <code>\u2013</code> (emdash) it works.</p>
  
  <pre><code>---
  title: "Untitled"
  author: "Llew Mills"
  date: "24 June 2016"
  output: pdf_document
  ---
  
  ```{r setup, include=FALSE}
  knitr::opts_chunk$set(fig.width=12, fig.height=8, fig.path='Figs/', 
                        echo=FALSE, warning=FALSE, message=FALSE, dev = 'pdf')
  ```
  
  ``` {r stuff}
  
  library(pander)
  
  m1 &lt;- rnorm(12,8,3)
  m2 &lt;- rnorm(12,4,5)
  m3 &lt;- rnorm(12,5,1)
  mR &lt;- rep("gene \u2013", 12)
  df &lt;- data.frame(mR,m1,m2,m3)
  
  pander(df, justify = "right", style = "simple")
  
  
  ```
  </code></pre>
  
  <p>However if instead of that unicode character I use the unicode for gamma <code>\u03B3</code> i get the error message <code>! Package inputenc Error: Unicode char \u8:γ not set up for use with LaTeX</code>.</p>
  
  <p>Does anyone know if there is a list of unicode characters that are compatible with LaTex, or alternatively a way to get latex to accept all unicode characters?</p>