setImmediate instead of nextTick for node v0.10.x

node is dropping support for nexTick as a trampoline
pull out the lambda

perhaps it reduces gc runs slightly
seperate features designed for making comparions into a seperate class

it was making the batch class hard to reason about
update comparison examples
add simple test for the comparison class
handle comparisons in the CLI
add support for `before` and `run`

`before` is really helpful for setting up the test environment
since its called with the exact number of iterations that are
to be run