org-plot.el: fix logic error in transposition

* lisp/org-plot.el (org-plot/gnuplot): If statement in transposition
treated condition as its negative, to fix this the condition was
inverted.

It was also noticed that the code could not operate as expected as the
user-supplied #+plot options were not fetched.  Resolved by re-inserting
relevant code from an older version of org-plot.

lisp/org-plot.el

@@ -580,6 +580,10 @@ line directly before or after the table."
     (dolist (pair org-plot/gnuplot-default-options)
       (unless (plist-member params (car pair))
 	(setf params (plist-put params (car pair) (cdr pair)))))
+    ;; Collect options.
+    (save-excursion (while (and (equal 0 (forward-line -1))
+				(looking-at "[[:space:]]*#\\+"))
+		      (setf params (org-plot/collect-options params))))
     ;; collect table and table information
     (let* ((data-file (make-temp-file "org-plot"))
 	   (table (let ((tbl (org-table-to-lisp)))
@@ -587,7 +591,7 @@ line directly before or after the table."
 			    ('y   t)
 			    ('yes t)
 			    ('t   t))
-		      (if (memq 'hline tbl)
+		      (if (not (memq 'hline tbl))
 			  (setq tbl (apply #'cl-mapcar #'list tbl))
 			;; When present, remove hlines as they can't (currentily) be easily transposed.
 			(setq tbl (apply #'cl-mapcar #'list