fix(serial): Disable serial logging by default

The serial console logging causes VirtualBox to consume an immense
amount of CPU, making coreos-vagrant nearly unusable. Disabling it
by default treats the problem until VirtualBox can fix the problem
upstream.
Merge pull request #85 from bcwaldon/disable-serial

Disable serial logging by default
feat(config): Use config.rb for configuration
Merge pull request #78 from bcwaldon/vagrantrc

feat(config): Use config.rb for configuration
Add a .gitattributes file to handle Unix files on Windows

We like to keep the LF line endings, instead of changing to CRLF
Change file after uploading from a Windows hosts to LF

We have to change the line endings from CRLF to LF, just removing all
CR characters.  If you don't do that, the IPv4 address will not set for
the network interfaces.
VirtualBox settings (vb.gui, memory, cpus) added to config.rb

Conflicts:
	Vagrantfile
Merge pull request #88 from DieterReuter/virtualbox-configs

VirtualBox settings (vb.gui, memory, cpus) added to config.rb
Update override-plugin.rb

With "temp.binmode" the file is written in LF only mode, even on a Windows host. That's all, no "tr" command is needed.
Refactor VirtualBox settings (use vb.memory, vb.cpus)
Merge pull request #89 from DieterReuter/refactor-vb-settings

Refactor VirtualBox settings (use vb.memory, vb.cpus)
Fixed typo in .gitattributes
Merge pull request #87 from DieterReuter/windows-crlf

Mods for using on a Windows host, use LF instead of CRLF line ending
feat(Vagrantfile) Use box versions, remove monkey patch.

As of 308 we generate json files that include version metadata for the
Vagrant boxes. Also the monkey patching has been moved into the box so
it can be removed from here.

Note: The version constraint ensures new instances will download 308 or
later but this is not enforced on existing instances. Since the monkey
patching is required just to get previous versions of CoreOS to boot
users should not update to this revision if old instances are in use.
Merge pull request #95 from marineam/master

feat(Vagrantfile) Use box versions, remove monkey patch.
Add ability to port-forward TCP docker service to host machine

Vagrantfile will check if $expose_docker_tcp is set in config.rb, and
will forwad the docker port (tcp/4243) to the specified port on the host.

Service for docker to listen on port 4243 added to user-data.
Merge pull request #100 from mattbailey/master

Add ability to port-forward TCP docker service to host machine