Add more complete combinators

[pfultz2]

Add some more adaptors for more complete combinatory logic:

• B = compose
• C = flip
• K = always
• W = ???
• S = ???
• I = identity

So the S(ie application combinator) and the W(ie duplicate combinator) combinators are missing, which could be something like:

S(f, g)(xs...) == f(xs...)(g(xs...))
W(f)(xs...) == f(xs...)(xs...)

Also, even though the C combinator is like flip, it could also be defined as:

C(f)(xs...)(ys...) == f(ys...)(xs...)

There is also the monad bind that can be defined for functions, something like:

mbind(f, g)(xs...) == g(f(xs...))(xs...)