Do not allow VERSION to be overloaded by build system.

When integrating finit as a component in another system, that build
system may set VERSION as an environment variable for that OS -- we do
not want that version to be set as the version of finit.

Also, bump version to 2.0.1-dev for upcoming patch release cycle.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile

@@ -25,8 +25,8 @@
 	install-exec install-data install-dev		\
 	uninstall-exec uninstall-data uninstall-dev
 
-#VERSION    ?= $(shell git tag -l | tail -1)
-VERSION    ?= 2.0
+#VERSION     = $(shell git tag -l | tail -1)
+VERSION     = 2.0.1-dev
 NAME        = finit
 PKG         = $(NAME)-$(VERSION)
 DEV         = $(NAME)-dev