build: switch source archive to xz compression

Change-Id: I8ec1968161aa6c85bf9ba7dd7859e81b160fabfb
diff --git a/README-dev.md b/README-dev.md
index 2a028b8..4cd0ef9 100644
--- a/README-dev.md
+++ b/README-dev.md
@@ -1,9 +1,10 @@
-# Notes for ndn-tools Developers
+# Notes for ndn-tools developers
 
 ## Licensing Requirements
 
-Contributions to ndn-tools must be licensed under the GPL 3.0 or a compatible license.
-If you choose GPL 3.0, insert the following license boilerplate into all C++ source files:
+Contributions to ndn-tools must be licensed under the GPL v3 or a compatible license.
+If you choose the GPL v3, please use the following license boilerplate in all `.hpp`
+and `.cpp` files:
 
     /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
     /*
diff --git a/wscript b/wscript
index 2b0f21d..99283ed 100644
--- a/wscript
+++ b/wscript
@@ -144,7 +144,9 @@
         Logs.warn('%s is not writable (%s)' % (versionFile, e.strerror))
 
 def dist(ctx):
+    ctx.algo = 'tar.xz'
     version(ctx)
 
 def distcheck(ctx):
+    ctx.algo = 'tar.xz'
     version(ctx)