fix "necessarilly" typo
fixed typos found by topy in all Markdown files

Topy is available at https://github.com/intgr/topy.
Updated website documentation for graceful_halt_timeout

The default value in the code is actually 60 seconds, so now the docs match that.
Removed unused halt timeout and check interval settings.
Merge pull request #3598 from mitchellh/remove-halt-timeout-from-windows-guest

guests/windows: Removed unused halt timeout and check interval settings.
Merge pull request #3597 from mitchellh/update-website-docs-halt-timeout-default-value

website/docs: Updated website documentation for graceful_halt_timeout
Merge pull request #3595 from berendt/topy

website: fixed typos found by topy in all Markdown files
Merge pull request #3594 from aspiers/provider-config-doc-typo

website/docs: fix "necessarilly" typo
Display deprecation warning for unused halt config properties

halt_timeout and halt_check_interval will be removed in the next version of Vagrant, 1.7.
Merge pull request #3599 from mitchellh/deprecate-warnings-for-unused-halt-config-props

Display deprecation warning for unused halt config properties
Update CHANGELOG
core: provider has default priority of 5
core: default provider chosen by usability and prority
Update tests
core: more intuitive logic around default providers
core: Can exclude providers
providers/docker: lower priority

We do this mostly because Docker is the only provider that using it
requires some amount of Docker-specific knowledge. VirtualBox, VMware,
etc. kind of "just work". It is not the likely case that someone does
a `vagrant up` and expects Docker, at this point.
core: Fix some tests, revert a change
core: dup the provider options so we can't overwrite them
core: fix final test