Assist with https://github.com/fzakaria/slf4j-timbre/issues/20

Users have reported seeing `Wrong number of args (9) passed to: timbre/-log!`
errors via slf4j-timbre when upgrading from Timbre v4.4.0 -> v4.5.0.

slf4j-timbre already uses the correct public API (timbre/log!), so this looks
like an AOT issue: a compiled Timbre v4.4.0 `log!` macro expansion is calling
a `v4.5.0` `-log!` function and breaking.

Unfortunately, looks[1] like a user-level call to `lein clean` isn't enough to
resolve the issue. Might be that slf4j-timbre itself needs to be recompiled?

Whatever the underlying cause, this should be a reasonable workaround for now.

[1] : https://github.com/fzakaria/slf4j-timbre/issues/20#issuecomment-229254285

src/taoensso/timbre.cljx

@@ -358,7 +358,15 @@
   (infof ^:meta {:err (Exception. "ex")} "Hi %s" "steve"))
 
 (defn -log! "Core low-level log fn. Implementation detail!"
-  [config level ?ns-str ?file ?line msg-type ?err vargs_
+
+  ;; TODO Temp workaround for
+  ;; https://github.com/fzakaria/slf4j-timbre/issues/20 and similar AOT tools
+  ([config level ?ns-str ?file ?line msg-type ?err vargs_ ?base-data]
+   ;; (throw (ex-info "Invalid internal Timbre call. Please try run `lein clean` to clear out-of-date build artifacts." {}))
+   (-log! config level ?ns-str ?file ?line msg-type ?err vargs_
+     ?base-data nil))
+
+  ([config level ?ns-str ?file ?line msg-type ?err vargs_
     ?base-data callsite-id]
 
   (when (log? level ?ns-str config) ; Runtime check
@@ -490,7 +498,7 @@
                          (apfn data))))))))
            nil
            (:appenders config))))))
-  nil)
+  nil))
 
 (comment
   (-log! *config* :info nil nil nil :p :auto