Raise version number
Locker now dynamically adds a project specific bridge device

- Network related code has been moved the new network module
- netfilter rules have been modified for the new bridge
- Implemented automatic IP address assigning for bridges and containers
- Add the necessary rules to communicate in and out of the containers (like via lxcbr0)
- Add simple example file
- DNS servers in containers are set to some default values (Google's DNS)
- Added cleanup function to remove netfilter rules and the bridge
- Replaced needs_locker_table decorator by better solution in network module
- Replace conditions by list types get function with default value
- Added missing docstrings and cleanup due to pylint report
- Optionally validate YAML configuration with pykwalify module
- Test in setup.py if lxc module can be imported
- Extended README due to above changes
- Moved example files to docs/examples
- Suppress warning when Container.ports() is called indirectly
- The timeout for container shutdowns can now be configured
- Improved status output: ports are sorted, hide destination 0.0.0.0
- $fqdn can be used in volumes
- Raised version to 0.4.1