Enchancement: Add option to resume downloads.

The point is that you cannot resume a file due to connection breaks if you 
have bad connection. You have to spend a lot of time to get link from log 
file as well as the name of the file that was mget dwonloading movie to 
and tell wget to resume that file. Begginers wouldn't do that due to lack 
of computer skills.

Request:
- add option to resume broken download ie.: --resume <filename> <link> 
- add option ro resume broken package download ie.:  --resume --input 
<filename>