Some warnings/exceptions are incorrectly labelled

[charlietian19]

Eg things like restarts in rhc.py (line 114) (under algorithms). I can't really fork the entire repo over right now, but there are a few changes to these that could be made. Eg the exception states that restarts must be a positive integer, but some leeway is allowed for restarts=0, so this message could be "non-negative" instead. There are a few examples of these throughout the code that I can bring up as well