Images with same filename overwrite old images.

[tech4him1]

- Do you want to request a feature or report a bug?
bug
- What is the current behavior?
If an image is uploaded with the same filename as a current image, the current one will be overwritten with the new one.
- If the current behavior is a bug, please provide the steps to reproduce.

1. Create a post with an image.
2. Create a second post with a different image that has the same filename.
3. The original post will have the new image.

- What is the expected behavior?
The posts should have separate images.

One way to fix this would be to create a separate subdirectory in the media folder for each post's media.

[erquhart]

This will be addressed under #350, will close with that issue.