added module host

Add or remove entries in /etc/hosts using tasks:
- host: ip=127.0.0.1 hostname=localhost aliases=foobar.com,localhost.foobar.com
- host: ip=127.0.0.1 hostname=localhost state=present
- host: ip=192.168.1.1 state=absent
- host: hostname=localhost state=absent
- host: ip=::1 hostname=localhost aliases=ip6-localhost,ip6-loopback
host: updated version_added
host: code cleanup
Merge branch 'feature/host' of https://github.com/resmo/ansible into resmo-feature/host
Fixing some bugs found during testing in the host module