title: Interpolate zoo object with missing Dates
body: <p>I have a climate time series with missing Dates (not missing values). For example:</p>
  
  <pre><code>n = 15
  full.dates = seq(Sys.Date(), by = 'day', length = n)
  serie.dates = full.dates[c(1:10, 12, 15)] # missing 11, 13, 14
  y = rnorm(n)
  
  require(zoo)    
  serie = zoo(y, serie.dates)
  </code></pre>
  
  <p>How can i 'fill' (using interpolation) these missing points, given the 'full.dates' vector?
  Thanks!</p>