export 'compatible'
export 'Compatible'.

elaborate documentation for Compatible.
elaborate documentation for numeric value operation instances.
Merge branch 'lightning' of github.com:goldfirere/units into lightning
Add QuOfUL (Build Qu from a unit and an lcsu).
change the operator names.
add fixty for qApprox and qNapprox
export the quantity type (but not the constructors)
hide the utility scripts under attic/
add an interesting example.
add more comments on the sample.
Fix TM's problem in PhysicalConstants.

Also, removed Poly, as we actually *are* designing a library for
polymorphic use!
RAE has fixed the problem!

Note: be aware of the side effects.
try define planck second as well.
add fromDefaultLCSU.

improve the documentations.
a slight improvement in the documentation.
improve documentation of qApprox
improve documentations in numIn and quOf
Use NegList instead of ('[] @- ...).
Fix UnicornHorn problem.

The basic problem was that, previously, DefaultLCSU meant that
the quantity was stored as a canonical unit... *any* canonical
unit. So, if there were two canonical units of the same dimension
(which we allow, in order to express two non-convertible units
of the same dimension), we would get bogus answers.

The new solution is to have a new open type family
DefaultUnitOfDim, which defines the representation of a
DefaultLCSU. So, if a user wishes to use a DefaultLCSU, they
must fix the mapping from dims to units by using this type
family. Then, a quantity in the default LCSU has a known
representation. Converting into and out of the default LCSU
makes sure that the target (other) LCSU has known conversions
to/from the global default.

There is a fair amount of other refactoring going on in this
commit, too.