title: Converting R Column names into id variables
body: <p>I'm quite confused and haven't even been able to search for what I'm looking for. I have a multi-year survey on different countries, which is currently like this: <br></p>
  
  <pre>        Question  Year  CountryA  CountryB  ...  CountryZ
          1         1999       Yes        No             No 
          2         1999       Yes        Yes            Yes</pre>
  
  <p>That is, it's currently organized by question. I want to have the data arranged by country, year and question number as such: <br> <pre>
  Country  Year  Question  Answer
        A  1999         1     Yes
        A  1999         2     Yes
        B  1999         1      No
        B  1999         2     Yes</p>
  
  <p></pre>
  And so on. Is this even possible? I can't seem to find anything to guide me to the right answer.<br> Thanks in advance!</p>