Marked the two new LogicGrowsOnTrees helper functions as being INLINEABLE.
Wrote a benchmark of how much mzero costs.
Fixed documentation typos.
Fixed glitches in the benchmark that were caching intermediate values.

This caused the benchmarks in question to under-estimate
the time by re-using values from previous iterations.
Wrote lopsided tree benchmark.
Created a null lopsided tree benchmark.
Deleted extraneous whitespace.
Created benchmark that measures the cost of >> and >>=.
Added a benchmark that mixes bind and plus.
Wrote a benchmark that measures the cost of fmap.