This PR is a follow up to #848 as per TerminX's request for additional settings for analog stick support.

It does the follow changes:

• Use floating point for calculating saturating and exponent
• Adds a new setting called 'snap zone' which controls the 'bowtie' deadzone when leaning towards an axis (as penned in this 2013 article)
• Adds a new function to Mact to visualize the deadzone/snapzone/saturation scale to a given tile pointer

The new code comes from the above article and uses this article (web demo here) as a reference for the math formula for the scaled axis deadzone.