um-next takes a list of tags, as a comma separated string

remove the '+' logic from the shell component.

i'm getting closer to just moving all logic into elisp. but that awk is so great.

elisp/um.el

@@ -201,19 +201,24 @@ NOTE: this searches in the current project root only.
 ;; shell integration
 
 ;;;###autoload
-(defun um-next (next-file &optional tag skip-header)
+(defun um-next (next-file &optional tags skip-header)
   "Takes the next-file generated by the shell script and opens it.
 
-With the optional tag generated by the script.
-And the option not to insert the um-journal-header.
+Optional TAGS string may contain more than one tag separated by a comma.
+The SKIP-HEADER option says not to insert the um-journal-header at all,
+in which case TAGS is also ignored.
 "
- (find-file next-file)
+  (find-file next-file)
   (unless skip-header
-      (um-journal-header)
-      (if tag
-          (progn (forward-line -1)
-                 (insert (format "+ %s\n" tag))
-                 (forward-line))))
+    (um-journal-header)
+    (if tags
+        (progn (forward-line -1)
+               (dolist (tag (split-string tags ","))
+                 (insert (format "+ %s\n"
+                                 (if (equal "+" tag)
+                                     (cadr (split-string next-file "\\."))
+                                   tag))))
+               (forward-line))))
   (message (format "creating %s" next-file))
   )