Update to FNMA 2-4 Unit (1-4 Investment) MI Dropoff

DocMagic is updating the configuration option used for selecting the FNMA rules for MI dropoff for 2-4 unit primary residences and 1-4 unit investment properties.   For these properties, MI is eligible to be terminated on the first day of the month after the date that is the mid-point of the original amortization period.  DocMagic added this configuration option late in 2017 but has now updated the calculation to consider additional property types: Condo, Co-operative, Manufactured Housing, Manufactured Housing/Condo, Manufactured Housing/PUD, PUD.