Logic that handles null values & doesnt break, changed inputtype number

Changed input type to number to when so that when field is blank the value is null, then added logic to handle null values.  Also changed how we set minimumQuantity when it is less than maximum quantity so that it no longer breaks.  There are two issues Reyjay will be resolving with css/html moving forward.  He will be making a decision on the style of (if we even keep) the default mouse wheel, and what happens when the user attempts to input a string value.  This PR fixes the original issue and enables Reyjay to move forward with his fixes.  You may want to wait for his fixes before merging in.