mindreader should log less when overrunning the buffer

[matthewdarwin]

When the buffer is too small, mindreader logs a lot like this:

(mindreader-stdin) reading from console logs (mindreader/mindreader.go:245){"error": "bufio.Scanner: token too long"}

This happens 100s of times per second. Totally waste of space and CPU.

Not sure if anything actually gets processed when this happens, or it is just in an infinite loop.