Add project and deadline properties

* ogi.el (ogi--project): New "internal" variable.
  (ogi-insert-entry): Add `GH_PROJECT' property to identify which
  github property an entry came from.  Only add a `MILESTONE' property
  when it has a name (as in, when it exists).  Add a `DEADLINE' to the
  entry if the milestone has a due date.
  (ogi-get-for): Rename from `ogi-insert', which is kind of
  non-descript.  Bind `ogi--project' to whichever project we're
  fetching so other functions can use it.

ogi.el

@@ -28,6 +28,9 @@
 
 ;;; Code:
 
+(defvar ogi--project nil
+  "Container for the name of the project we're fetching.")
+
 (defun ogi-get (project)
   "Get a list of open issues for PROJECT."
   (let* ((url-request-extra-headers
@@ -68,14 +71,26 @@
                                  (replace-regexp-in-string
                                   "-" "_" (ogiprop itm name)))
                                (ogiprop issue labels)))
-      (org-entry-put (point) "ID" id))))
+      (org-entry-put (point) "ID" id)
+      (org-entry-put (point) "GH_PROJECT" ogi--project)
+
+      (let* ((milestone (ogiprop issue milestone))
+             (title (ogiprop milestone title))
+             (due-on (ogiprop milestone due_on)))
+        (when title
+          (org-entry-put (point) "MILESTONE" title)
+          (when due-on
+            (message due-on)
+            (org-deadline
+             nil (replace-regexp-in-string "[TZ]" " " due-on))))))))
 
 ;;;###autoload
-(defun ogi-insert (project)
+(defun ogi-get-for (project)
   "Insert (new) issues for PROJECT under the current entry."
   (interactive "MGet issues for: ")
   (goto-char (point-max))
-  (mapc #'ogi-insert-entry (ogi-get project)))
+  (let ((ogi--project project))
+    (mapc #'ogi-insert-entry (ogi-get project))))
 
 (provide 'ogi)