Makefile.defs: version set to 5.1.0-dev0

- development for future release series 5.1.x is open

src/Makefile.defs

@@ -105,9 +105,9 @@ INSTALL_FLAVOUR=$(FLAVOUR)
 
 # version number
 VERSION = 5
-PATCHLEVEL = 0
+PATCHLEVEL = 1
 SUBLEVEL =  0
-EXTRAVERSION = -pre2
+EXTRAVERSION = -dev0
 
 # memory manager switcher
 # 0 - f_malloc (fast malloc)