Merge pull request #109 from BlythMeister/ImageCache

Change image cache to only ever have 1 days worth of images in any cach
Add minimum height to direct message compose box so as the character count shows.

This fixes #106
Add overide to spotlight so that the reply box is re-populated with the correct details.

This only effects the spotlight, and not the main feed reply.
This fixes #107
Do not subtract 1 from new tweet count and display if the new tweet number is greater than 0

This does mean that you can get a message saying "1 new tweet"
Fixes issue #111