Rename 'ensure' to 'state' because I think it's a bit cleaner and doesn't imply

all modules take a common parameter name.  But more or less we still work idempotently
in modules.

library/git

@@ -16,7 +16,7 @@ import shlex
 import subprocess
 
 # ===========================================
-# convert arguments of form ensure=running name=foo
+# convert arguments of form a=b c=d
 # to a dictionary
 # FIXME: make more idiomatic