title: LilyPond: acciaccaturas and slashed stems not showing when beamed together
body: <p>I have a question related to acciaccaturas and slashed stems. So the first one is: why when more than one note is input as acciaccaturas or slashed grace notes they are not automatically beamed? And why when I beam them I lose the slash?</p>
  
  <pre><code>\version "2.17.26"
  {
    \relative c''{
      \time 3/4 {
        \acciaccatura e8 c4 \acciaccatura { e8 d } c4 \acciaccatura { e8[ d] } c4 |
        \slashedGrace e8 c4 \slashedGrace { e8 d } c4 \slashedGrace { e8[ d] } c4
      }
    }
  }
  </code></pre>
  
  <p>In my opinion, the last note of each bar should be as:</p>
  
  <p><img src="https://i.stack.imgur.com/MtzRQ.gif" alt="enter image description here"></p>
  
  <hr>
  
  <p>Something similar (related to the slashed stem), but now on regular notes. When I compile the code below, I get what I want: 4 unbeamed notes, and the first has a slash on its stem.</p>
  
  <pre><code>\version "2.17.26"
  {
  \autoBeamOff
  \relative c''{
      \once \override Flag #'stroke-style = #"grace" c8
      c c c r4 r2 |
    }
  }
  </code></pre>
  
  <p>Now if I remove the line <code>\autoBeamOff</code>, the notes will be beamed but without the slash on the first!</p>
  
  <p>I would be very thankful if someone could help me out with these problems.</p>