Generalized keys, values, assocPartialU and dissocPartialU to allow
objects with constructor other than Object.
Removed pipe, pipe2, pipe3, pipe4 and added just pipe2U and
compose2U instead.
Changed the semantics of curryN to support staged functions. Previously
curryN(n, fn) changed the arity of the given function fn to n. Now the
n signifies the total number of arguments and the function is allowed to be
staged.
Added arityN(n, fn) to set the arity of a given function fn to n and also
to curry the function.
Removed assert. It is better to explicitly compare against
process.env.NODE_ENV in libraries, because this allows minifiers to eliminate
the assertions.
Removed
mapPartialUzipObjPartialUunzipObj
because their functionality turned out to be be too specialized.