Expose logger property

Logger can be be omitted without defaulting to console. The logger can be set to a new value at any time.
Merge pull request #8 from Springworks/feature/opt-logger

Expose logger property
Update version
Added OS specific files to .gitignore
Using an empty object instead of null as logger.

The logger was spamming the test output to much.
Improvements in the open-statement of the connection.

Added default connection options with connection timeout,
and switched the `open()` statement to `openSet()`.

Conflicts:
	index.js