We were tracking flushing using one variable while there
were in fact two types of flushing. This commit remedies that
And furthermore adds a check for function streams
whether their listeners need updating at the end of
updateStream

This also has some general code quality improvements 
including variable name changes

The change made in the last commit accidentally removed the ability
To update a stream often inside a stream body.

This helps with debugging (you don't have to step through ramda's curry while debugging)

Now that multi level dependent streams work we need
switchLatest to not end its stream immediately because one of the streams in the merged end streams has a value right now.

…a stream value currently