Merge pull request #1117 from tubalmartin/Upload|library|2.1-stable

2.1 stable - CI_Upload::_file_mime_type() could've failed if popen() is used for the detection.
tree: 03e3ef0375a4831dd63e657866e582271a0a326c
  1. .gitignore
  2. application/
  3. index.php
  4. license.txt
  5. system/
  6. user_guide/