Add tls and filename for index file

[angaz]

Added support for TLS. Added --tls flag which copies the way redis-cli works.

Also added a flag to place the index file in a specified filename. I needed this because I ran the tool for multiple clusters at the same time.

I also moved up creating the file because once it ran for about an hour and then couldn't create the file. So now it will fail earlier.

I couldn't decide where to put the new flags that I added, so I sorted the flags by name.