Ensuring syslog async socket writer and waitForProcess asyncs are GCd

Fixes #15
Merge pull request #16 from brendanhay/feature/cleanup

Ensuring all asyncs are canceld on signal receive or termination
Bumping version to 0.4.1
Merge branch 'release/0.3.1'
Bumping version to 0.4.1
Merge branch 'release/0.4.1'