Add support for enforcing single line log entries #1

I'd forgotten to add this when writing the initial release, and it's pretty important seeing as it's the default for most logging systems where newlines show new entries

Proposal:

Option to have single line log-entries, removing newlines when logging
Option to define the newline: unix, windows, and maybe classic mac?

Also, maybe a clear boundary between log entries should be determined for the default newline-allowing format? Perhaps a double-newline (empty line) separator?