restore imgMetadata dict (#858)

* Revert "memory optimization: store metadata in filenames, not a global dict (…"

This reverts commit 9a2a09eab9.

* only remove imgOld

kindlecomicconverter/image.py

@@ -299,12 +299,13 @@ class ComicPage:
 
     def saveToDir(self):
         try:
+            flags = []
             if not self.opt.forcecolor and not self.opt.forcepng:
                 self.image = self.image.convert('L')
             if self.rotated:
-                self.targetPath += '-Rotated'
+                flags.append('Rotated')
             if self.fill != 'white':
-                self.targetPath += '-BlackBackground'
+                flags.append('BlackBackground')
             if self.opt.forcepng:
                 self.image.info["transparency"] = None
                 self.targetPath += '.png'
@@ -322,7 +323,7 @@ class ComicPage:
                     self.image.save(self.targetPath, 'JPEG', optimize=1, quality=85)
             if os.path.isfile(self.orgPath):
                 os.remove(self.orgPath)
-            return Path(self.targetPath).name
+            return [Path(self.targetPath).name, flags]
         except IOError as err:
             raise RuntimeError('Cannot save image. ' + str(err))