Update version to 0.9.15 in preparation for making a release

 -Erik

Rules.mak

@@ -26,7 +26,7 @@
 # Be sure to update include/features.h when changing this...
 MAJOR_VERSION:=0
 MINOR_VERSION:=9
-SUBLEVEL:=14
+SUBLEVEL:=15
 VERSION:=$(MAJOR_VERSION).$(MINOR_VERSION).$(SUBLEVEL)