title: fread data.table in R doesn't read in column names
body: <p>When reading in a data file into R, I can read it in either as a <code>data.frame</code> or a <code>data.table</code> using the <code>data.table</code> package.  I would prefer to use <code>data.table</code> in the future since it deals with large data better.  However, there are issues with both methods (<code>read.table</code> for data.frames, <code>fread</code> for data.tables) and I'm wondering if there's a simple fix out there.</p>
  
  <p>When I use <code>read.table</code> to produce a <code>data.frame</code>, if my column names include colons or spaces, they are replaced by periods, which I do not want.  I want the column names to be read in "as is."</p>
  
  <p>Alternatively, when I use <code>fread</code> to produce a <code>data.table</code>, my column names are not read in at all, which is obviously not desired.</p>
  
  <p>Check out this gist below for a reproducible example:</p>
  
  <p><a href="https://gist.github.com/jeffbruce/b966d41eedc2662bbd4a" rel="nofollow">https://gist.github.com/jeffbruce/b966d41eedc2662bbd4a</a></p>
  
  <p>Cheers</p>