Fix install instructions of blender export on a mac to what works and is...

Fix install instructions of blender export on a mac to what works and is recommended now. fixes #6994

Further improvements to the process are possible too (provide zip or make blender support installing py packages from dirs and not only zips, see issue for details)

utils/exporters/blender/README.md

@@ -30,13 +30,9 @@ OR (for 2.6)
 
 ### OSX
 
-Depends on where blender.app is. Assuming you copied it to your Applications folder:
+In your user's library for user installed Blender addons:
 
-    /Applications/blender.app/Contents/Resources/2.7X/scripts/addons
-    
-OR (for 2.6)
-
-    /Applications/blender.app/Contents/MacOS/2.6X/scripts/addons
+    /Users/(myuser)/Library/Application Support/Blender/2.7X/scripts/addons
 
 ### Linux