title: ndk build library outside main project source tree
body: <p>I wants to build a 3rd party library avahi using ndk. avahi has android port already (with valid Android.mk). </p>
  
  <p>What I have done: 
  I have successfully created a project and copied all the source code in to jni/ folder and run ndk-build. It builds libavahi.so</p>
  
  <p>What I wants to do:
  Instead of copying all the source code into jni/ folder, I'd like to store it in a folder outside project source tree. What shall I do? I have looked into NDK DOCUMENTATION/Import Module but nothing is similar to my case. </p>
  
  <p>Newbie in ndk, and any suggestion is welcomed. </p>