(FACT-617) Facter README.md should express semver

The puppet readme (https://github.com/puppetlabs/puppet/blob/master/README.md)
explains the maintenance we have for versions of puppet and that it is
semantically versioned. We recently encountered an issue with Facter where
users were surprised that we did not ship a security release for a previous
major version of facter. The previous assumption may have been that the puppet
README was sufficient for all of our FOSS projects, but this is probably not
the case. We should update the README.md in facter with the same verbage as
puppet so our intended release lifecycle is clear.

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
(FACT-612) Add structured uptime fact

This commit adds a new 'system_uptime' structured fact, which
includes keys for seconds, hours, days and uptime. Also,
the existing uptime facts have been modified to use this hash rather
than calling out to Facter::Util::Uptime utilities to generate their
values.
(MAINT) Replace bare 'sysctl' call with Facter::Util::POSIX.sysctl

This commit builds on work done in proposed pull request
715 by jasperla, and uses the existing sysctl method to find kern.boottime,
rather than doing a bare Facter::Core::Execution call on sysctl.
Merge pull request #721 from whopper/structured_uptime_fact_master

(FACT-612) Add structured uptime fact
(doc) Update comment docs formatting

The docs team can now automatically extract comment docs from facts, but
that means that the comment docs have to be formatted just a bit more
consistently now. I've reformatted the ones that needed it. There are no
changes to actual code. There's some information about the formatting
standard I'm using in the README at github.com/holguinj/extracter
(FACT-612) Fix issue with missing POSIX require

This commit fixes an issue where in OSX, system_uptime
would fail due to a missing requirement of 'facter/util/posix'
in uptime's utility file.
Merge pull request #726 from whopper/uptime_posix_require_fix

(FACT-612) Fix issue with missing POSIX requirement for system_uptime
(FACT-603) Allow acceptance to use github mirror

This provides the necessary bits to allow facter to use github mirrors during
acceptance runs.
Merge branch 'ticket/stable/FACT-603-use-github-mirror' into stable

* ticket/stable/FACT-603-use-github-mirror:
  (FACT-603) Allow acceptance to use github mirror
Merge branch 'stable'

* stable:
  (FACT-603) Allow acceptance to use github mirror
(maint) ignore .idea folder
(FACT-569) Acceptance - switch ruby based on ruby_arch

 - In the host config, specify ruby_arch and either x86 or x64 to switch which
version of ruby that is used.
(maint) Acceptance gemfile/.gitignore updates

 - Pins beaker and rake to the same version as with puppet
 - Adds acceptance/.gitigore to ignore the files/folders that are generated
and/or used with beaker runs.
(maint) Acceptance: timesync should no longer be required
(maint) Acceptance - use user's Acceptance SSH key

This change moves id_rsa_acceptance from being required in the acceptance
folder to ~/.ssh/id_rsa_acceptance by default. The build servers override the
location of this file so it should have a low impact of change.
(maint) Acceptance - preserve hosts on fail

This allows hosts to stick around on failure so that issues can later be
evaluated.
(maint) Acceptance nodes - remove unnecessary config

 - Removes the following from under `CONFIG:` if it was found in any of the
node yaml files. This option is deprecated and no longer necessary.

        filecount: 12

 - Ensures master roles are only master and agent. Some node configs had
database/dashboard listed, which would add time and are likely unnecessary for
testing in FOSS.
(FACT-569) Acceptance nodes - Windows Ruby-x64 configs

Adds windows nodes with x64 configurations.
Updates x86 nodes with explicit architecture setting
Merge remote-tracking branch 'ferventcoder/ticket/stable/FACT-569-acceptance-win-ruby-x64' into stable

* ferventcoder/ticket/stable/FACT-569-acceptance-win-ruby-x64:
  (FACT-569) Acceptance nodes - Windows Ruby-x64 configs
  (maint) Acceptance nodes - remove unnecessary config
  (maint) Acceptance - preserve hosts on fail
  (maint) Acceptance - use user's Acceptance SSH key
  (maint) Acceptance: timesync should no longer be required
  (maint) Acceptance gemfile/.gitignore updates
  (FACT-569) Acceptance - switch ruby based on ruby_arch
  (maint) ignore .idea folder
Merge branch 'stable'

* stable:
  (FACT-569) Acceptance nodes - Windows Ruby-x64 configs
  (maint) Acceptance nodes - remove unnecessary config
  (maint) Acceptance - preserve hosts on fail
  (maint) Acceptance - use user's Acceptance SSH key
  (maint) Acceptance: timesync should no longer be required
  (maint) Acceptance gemfile/.gitignore updates
  (FACT-569) Acceptance - switch ruby based on ruby_arch
  (maint) ignore .idea folder