Update version logic

Allow any number of components, using only the first 3
for SQLite.  (SQLite used to be a lot less consistent.)

setup.py

@@ -107,8 +107,8 @@ def write_whole_file(name, mode, data):
 
 
 def sqliteversion(v):
-    assert len(v.split(".")) == 4
-    return v.rsplit(".", 1)[0]
+    assert len(v.split(".")) >= 4
+    return ".".join(v.split(".")[:3])
 
 
 # They keep messing with where files are in URI