title: JNI_VERSION_1_6 vs JNI_VERSION_1_4
body: <p>Hello I'm maintaining an Android JNI library that uses JNI_VERSION_1_4.</p>
  
  <p>I was wondering if I could change it to JNI_VERSION_1_6, but I didn't found any documentation explaining the differences between them.</p>
  
  <p>Are they changing any function?
  Is any one faster than the otherone?</p>
  
  <p>Thank you!</p>