ox-taskjuggler.el: Fix byte compiler warnings

* ox-taskjuggler.el (org-taskjuggler-get-project)
(org-taskjuggler-resolve-dependencies): Fix references to free
variables.

contrib/lisp/ox-taskjuggler.el

@@ -145,7 +145,9 @@
 ;;
 ;;; Code:
 
-(eval-when-compile (require 'cl))
+(eval-when-compile
+  (require 'cl)
+  (defvar build-id))
 
 (require 'ox)
 
@@ -433,13 +435,14 @@ INFO is a plist used as a communication channel.  First headline
 in buffer with `org-taskjuggler-project-tag' defines the project.
 If no such task is defined, pick the first headline in buffer.
 If there is no headline at all, return nil."
-  (or (org-element-map (plist-get info :parse-tree) 'headline
+  (let ((tree (plist-get info :parse-tree)))
+    (or (org-element-map tree 'headline
 	  (lambda (hl)
 	    (and (member org-taskjuggler-project-tag
 			 (org-export-get-tags hl info))
 		 hl))
 	  info t)
-      (org-element-map tree 'headline 'identity info t)))
+	(org-element-map tree 'headline 'identity info t))))
 
 (defun org-taskjuggler-get-id (item info)
   "Return id for task or resource ITEM.
@@ -573,7 +576,7 @@ DEPENDENCIES is list of dependencies for TASK, as returned by
 `org-taskjuggler-resolve-depedencies'.  TASK is a headline.
 INFO is a plist used as a communication channel.  Return value
 doesn't include leading \"depends\"."
-  (let ((dep-str (concat (org-element-property :BLOCKER task)
+  (let* ((dep-str (concat (org-element-property :BLOCKER task)
 			  " "
 			  (org-element-property :DEPENDS task)))
 	 (get-path