Save random quote queue

[smileyhead]

The random queues should be seeded and the seed and the index saved to a file every time a quote is recalled. When the bot restarts, it should check whether there is saved progress and load it if so.

[smileyhead]

Unfortunately, I realised this would not be possible without also saving the entire upcoming queue as a file every time a quote is recalled, due to the queue always changing. I do not believe that much disk usage is justifiable.

[smileyhead]

Reopening this issue with the following specifications:

When a quote queue is initially created (which isn't very often), the following file is created (or overwritten):

queue = [ 456, 123, 789, 52, 48, 153 ]
index = 0

Where queue is the entire quote queue, represented as an int array corresponding to quote indexes in the database, and index is the current position in the queue. Every time a quote is recalled, the index in the file is also updated. Since the index is stored at the very end of the file, and the rest of the data isn't touched, disk usage is negligible.

Restoring the queue from this file at start-up should be simple.