Bump version number.

Author: c-lipka

source/base/version.h

@@ -100,7 +100,7 @@
 /// where `N` is a serial number starting at 1 in each phase, `TIME` is the number of minutes
 /// since 2000-01-01 00:00, and `FEATURE` is an arbitrary alphanumeric moniker for a particular
 /// experimental feature.
-#define POV_RAY_PRERELEASE          "alpha.9811560"
+#define POV_RAY_PRERELEASE          "alpha.9841009"
 
 #if defined(DOXYGEN) && !defined(POV_RAY_PRERELEASE)
     // Work around doxygen being unable to document undefined macros.