Added possibility to resize EBS root disk on initial deployment. This will
allow instances to be created that need a bigger root disk than the default
20GB, e.g. for a bigger nix store (buildfarm or deployment servers).

Example usage:

  deployment.ec2.ebsInitialRootDiskSize = 100;
Perform remote builds on a single machine

Fixes issue #103.
Remove import of pre-SQLite state files
nixops list: Ignore deployments with unknown resource types

This provides some forward compatibility (e.g. if the state file
contains resources from the "next" branch such as EBS volumes).
Fix weird "cannot compare values of different types" error
Refactoring: Move state file handling into a class
Move StateFile into a separate file
Add a method to get all deployments (as objects)
Sort deployments by name
nixops list: Make column alignment more sensible
nixops dump-state: New command to dump a JSON serialisation of deployments

Issue #99.
Generalize handling of --all
Rename ‘dump-state’ to ‘export’
nixops import: Support importing deployments dumped by ‘nixops export’

Fixes #99.
Document export/import
Include machine's own hostname in /etc/hosts

This shouldn't be necessary due to our use of nss_myhostname, but it's
possible that <hostname>.<domainname> actually resolves (issue #106).
Adding it shouldn't hurt.

Fixes #106.
Exclude nixops export from syslog logging
nixops delete: Add --force flag
Improved error message if there are multiple deployments with the same name
nixops create: Use -d instead of -n to specify the name of the deployment

Fixes #90.