Improve RHEL support, better idempotent behavior

• #51: Make host file idempotent on RHEL
• #52: Add append_hostsfile_ip logic for improved idempotence
• #55: Ensure sysctl kernel.hostname set correctly on RHEL

improve logic around localhost, use of fqdn; bugfixes

• #43: Set unique hosts file entry for hostname
• #44: Make hostname mapping to 127.0.0.1 optional

Updates to resolve deprecations warnings and various test fixes

v0.4.0

• #40: Use file resources with lazy eval and notifies to prevent network restarts from occurring on every chef run (Matt Kasa)
• Add box with Ubuntu 14.04 for kitchen tests
• #27: Update default recipe to reload only the hostname plugin instead of ohai (Jonathan Serafini)