title: Remove trailing "=" when base64 encoding
body: <p>I am noticing that whenever I base64 encode a string, a "=" is appended at the end.  Can I remove this character and then reliably decode it later by adding it back, or is this dangerous?  In other words, is the "=" <strong>always</strong> appended, or only in certain cases?</p>
  
  <p>I want my encoded string to be as short as possible, that's why I want to know if I can always remove the "=" character and just add it back before decoding.</p>