initial patterns don't check for units

[lgwagner]

a01 = initial :: water_lvl == 0.0 m;    
a02 = global :: always water_lvl >= 0.0 m;

if water_lvl is of unit m the second requirement a02 throws a validation error, but the a01 requirement does not throw a validation error when the units are missing on the value.

[AFifarek]

The last time I looked the unit type checking is not functioning. We will have to look into this and figure out what is going on.