including external code under apache 2.0

[Prescott Nasser]

Hey all, We've had a community member port a library for Lucene.Net that we'd 
like to include in our contrib packages. The package is under the apache 2.0 
license, so we think we are in the clear to include the code into our contrib 
package - but we weren't sure and just wanted to double check. The contrib 
project is located here: https://github.com/synhershko/Spatial4n Thanks for 
your guidance~Prescott