Add alerts

[Insprill]

Alerts to signal when an action failed (or succeeded?) should be implemented. These could be implemented similarly to Psst, as that would work fairly well with the small window size. Perhaps there could be a limit to the maximum amount of notifications shown on screen at once, not allowing it to take up more than half, or three-quarters of the window size.

Some refactoring may have to be done to ensure error messages are useful and contain the appropriate amount of information to fix the issue or ask for help.