Start 1.18.0 development cycle

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/Makefile b/Makefile
index 83a9128..2d6a3b2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 1
-PATCHLEVEL = 17
+PATCHLEVEL = 18
 SUBLEVEL = 0
-EXTRAVERSION =
+EXTRAVERSION = .git
 NAME = Unnamed
 
 # *DOCUMENTATION*