Add type synonyms for the common types of functions on streams
Use CPP to clean up conduit fusion, move stream versions into separate module
Remove some unnecessary imports
Derive functor for Stream (useful in a function in conduit-combinators)
Move list quickcheck tests into a new module + finish the tests

Currently 4 tests are commented out as I can't figure out how to
simply implement checkConduitResultM'
Add ".hsenv/" to .gitignore
Add "fusion-macros.h" to extra-source-files, to fix sdist build
Comment out unimplemented "checkConduitResult*" functions in test
Add a benchmark of fusion for a couple functions

While we don't have benchmark coverage, this does cover both CPP macros used for implementing fusion
Make the streaming version of groupBy slightly more efficient
Increment conduit minor version