Raise a proper SSH error on EHOSTUNREACH
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