Fix typo.
Vagrant::Action::Builder RDoc correction

The RDoc comments for `Vagrant::Action::Builder#to_app` reference an
instance of `Vagrant::Action::Environment` as the passed paramter. There
is no class `Vagrant::Action::Environment` available. The param being
passed is actually a `Hash` that represents the "action environment".

This commit corrects the RDoc lines for
`Vagrant::Action::Builder#to_app` to correctly reference the passed
`Hash`.
Raise a proper SSH error on EHOSTUNREACH
Remove duplicate entry in en.yml

Key vagrant.config.vm.network_ip_required appears twice. Remove the unused entry.
Merge pull request #1912 from emyl/locales_cleanup

Remove duplicate entry in en.yml
Merge pull request #1861 from trlinkin/rdoc_builder

Vagrant::Action::Builder RDoc correction
Merge pull request #1720 from tawan/patch-1

Fix typo.
Support Fedora when it was "Fedora Core"

The version_number regex was causing an error because my /etc/redhat-release looks like this:

Fedora Core release 6 (Zod)

This fix allowed initialize to run just fine on my ridiculously old release.
Merge pull request #1913 from mightybs/master

Stop ruby regex error on "Fedora Core" releases.
Merge pull request #1911 from emyl/no_route_fix

Raise a proper SSH error on EHOSTUNREACH
Update CHANGELOG
v1.2.3