2015-09-24: state explicitly in NEWS that installing no longer depends on

state explicitly in NEWS that installing no longer depends on Python.

diff --git a/NEWS b/NEWS
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ wisp 0.9.0 (2015-09-24):
 - actually distribute wisp.scm
 - wisp now starts from wisp.scm. To bootstrap a release from Python, 
   remove wisp.scm and run `make wisp.scm`
+  starting with 0.9.0, installing wisp no longer depends on Python.
 
 wisp 0.8.7 (2015-09-24):
 - new example say.w, companion to