Adds support for building facter on RHEL7 via spec.
Add initial support for building in a RHEL 7 mock

RHEL7 support is being added for x86_64 only; we'll fix/expand
this if upstream releases a 32-bit version of RHEL7.
Merge pull request #616 from mckern/add-el7-to-stable

Apply the RHEL7 work and merge it into stable
(packaging) Update FACTERVERSION to 1.7.5-rc2
(packaging) Update FACTERVERSION to 1.7.5
(FACT-346) Remove selinux_mode from schema

The selinux_mode fact was removed in 544260f, removing from the schema
also.
(FACT-349) Surface error messages when rescuing exceptions
Merge pull request #647 from adrienthebo/feature/facter-2/log-exceptions

(FACT-349) Surface error messages when rescuing exceptions
(maint) Handle string output in zfs/zpool version facts
Merge branch 'maint/facter-2/zfs-version-empty' into facter-2
(FACT-351) Fix netmask fact on Darwin and *BSD

During facter2 development, the method_missing logic for resolving fact
values has been removed, e.g. Facter.ipaddress. There was one case left
over that when called would produce:

    Could not retrieve fact='netmask', resolution='<anonymous>':
    undefined method `ipaddress' for Facter:Module

and no backtrace.

This commit patches up the fact and adds a spec test.
Merge pull request #648 from joshcooper/issue/facter-2/FACT-351-undefined-method

(FACT-351) Fix netmask fact on Darwin and *BSD
(maint) Simplify aggregate error message
Merge branch 'maint/facter-2/clearer-aggregate-error' into facter-2
Merge branch 'stable' into facter-2