core: Remove Vagrant::Hosts and add Vagrant::Host, a CapabilityHost
core: Modify plugin interfaces and API for hosts
core: whitespace
core: Vagrant::Environment uses new host settings
Get tests to pass
core: pass environment into all host caps
hosts/bsd: convert to new style
convert more hosts: arch and linux
hosts/freebsd: convert
many more hosts converted
hosts/windows: convert
hosts/null: needs to accept env as param
core: event he default host shuld have proper API
hosts/*: proper detect API
kernel/v2: a host always exists, remove dumb check
website/docs: document host capabilities
Merge pull request #2784 from mitchellh/f-host-capabilities

Host Capabilities
Update CHANGELOG
website/docs: tips & tricks for vfile [GH-2788]
core: has_plugin? uses the new plugin manager class to check for gems