Add Float.round function

Float.round allows rounding floats to arbitrary precision, as well
as specifying how midpoint rounding is performed (up/down).
Ensure suspensions are closed on failures
Merge pull request #1927 from bitwalker/master

Add Float.round function
Cleaning up Stream docs
Merge pull request #1930 from jwarwick/stream_docs

Cleaning up Stream docs
Correct the function name in Stream.take_every spec
Merge pull request #1932 from pminten/correct-stream-take-every-spec

Correct the function name in Stream.take_every spec