fix an infinite loop when the token dispenser is having issues

[dilinger]

When searching or downloading apks, gplaycli will happily keeping to get a token over and over from the token dispenser. If the token dispenser spits out tokens but google doesn't like them, it will create an infinite loop.

This breaks out of that loop after 5 attempts, and also suggest to the user that they try using their own credentials. I'd like to point them to a manpage or README with instructions, but we're not there yet.

[eighthave]

As a user, this would be great to have! Maybe it should be enabled using a option flag? Make the default be the current behavior, then it would be something like --token-retries=5

[fontanon]

Worked for me !