Creating new types breaks precompilation

[bc0n]

In the current macros, new types are created in UnitTypes' namespace but this breaks precompilation:

ERROR: LoadError: Evaluation into the closed module `UnitTypes` breaks incremental compilation because the side effects will not be permanent. This is likely due to some other 
module mutating `UnitTypes` with `eval` during precompilation - don't do this.
...
in expression starting at W:\mechgits\julia\Geometry2D_public\src\Spiral2D.jl:18 
...
@makeBaseMeasure Pitch MeterPerRev "m/rev"

[bc0n]

The solution appears to be evaluating in the calling namespace, changing makeSelfConversion() and makeJointConversion() from

    UnitTypes.eval( quote ...

to

    @__MODULE__.eval( quote 

but @__MODULE__ isn't defined when makeSelfConversion actually runs, so I need to pass in its value at macro expansion time:

function makeSelfConversion(newType, mod=@__MODULE__)
     mod.eval( quote 

where the call in @makeBaseMeasure is

    UnitTypes.makeSelfConversion($newType, @__MODULE__)