changed overlay_watermark() to check for an alpha value before applying the image to help support PNG-24s with alpha transparency

http://codeigniter.com/bug_tracker/bug/4506/
2 files changed
tree: ddc1eccf593a16b2dae9c5c2756a5185f047f0c8
  1. index.php
  2. license.txt
  3. system/
  4. user_guide/