Add config['sleep'] to dummy driver in order to simulate work.
Ensure all Instance action methods return self.
Add minimal system logging and a file logger per Instance.
[Instance#driver] Move Driver from Platform to Instance.

This is a major refactoring of the codebase. In light of the increasing
number of collaborators passed into Instance.new, its constructor was
changed to an options hash which is more in line with Suite.new and
Platform.new.
Remove Driver::Base#instance from its public API, now protected.
Add Logging#debug.
Move Jamie::Config::DEFAULT_LOG_LEVEL to Jamie::DEFAULT_LOG_LEVEL.
Set log levels for Jamie.logging and Instance#logger.
Add Jamie::Logging to Jamie::Driver::Base and override #puts & #print.
Update Jamie::Driver::Dummy to use logging facility.
Add Jamie::Logger to handle multi-format, multi-output logging.
Clean up console and logfile output thanks to new Logger.
[Driver API] Drop instance parameter in action methods.

Now that a Driver is given a reference to its instance after creation,
the instance is available via the #instance message.
Use logger level when running chef-solo in Jamie::Driver::SSHBase.
Improve logging in cookbook artifact uploading.
Remove extra banner logging statement.
Measure action execution times & report them consistently.
Generate methods for Jamie::Logging.
Reformat output from jr to use local log method calls.

In other words a remote jr banner() log line will correspond to a local
Jamie #banner log line.
Instance loggers now append to their log file.