Removed InterfaceHasAliases.

It was removed bcs:
- referenced NetworkInterfaces.HasAliases is not available in latest
  yast2 anymore
- it didn't worked well even before
Updated changelog
Merge pull request #122 from mchf/master

Removed InterfaceHasAliases.
Exclude ifplugd device from bridge ports candidates. bnc#847783
Updated changelog
Updated spec
Replaced oldfashioned bridge testsuite using rspec and extended.
Enabled routing rspec test
Added comment, adapt to style guide.
Merge pull request #123 from mchf/bnc847783-bridge-ports

Do not propose 'ifplugd' devices as bridge ports
Add CONTRIBUTING.md

See:

  * https://github.com/blog/1184-contributing-guidelines
  * http://lists.opensuse.org/yast-devel/2013-10/msg00052.html
remove privatelly exported attribute access
Merge pull request #127 from yast/change_devices_tests

remove privatelly exported attribute access
Always write firewall configuration
Updated changelog

Conflicts:
	VERSION
	package/yast2-network.changes
Merge pull request #129 from mchf/bnc843646-cannot-disable-firewall

Firewall can be enabled / disabled during installation.
Removed spec template
Updated spec
fix dropped attribute accessor
changes