(maint) Add real case for autosign cert generation test

Nate Wolfe noticed what looks like a copy paste error in my original
ssl/puppet_cert_generate_and_autosign.rb test that was repeating the
cert generate with autosign false and dns_alt_names case for the
autosign true and dns_alt_names case. This commit replaces that with
tests using autosign true, which on master with ca fails, and requires
manual signing with --allow-dns-alt-names flag.
(doc) Document user :system param only applies on create
(doc) Fixes simple typo in 'parser' section.

Also present in https://github.com/puppetlabs/puppet-docs repo. Related Pull Request submitted: https://github.com/puppetlabs/puppet-docs/pull/345.
Merge pull request #2850 from adrienthebo/doc/master/user-system-parameter

(doc) Document user :system param only applies on create
Merge pull request #2861 from jpartlow/maint/master/fix-puppet-cert-generate-testcase-with-autosign-and-dns-alt-names

(maint) Add real case for autosign cert generation test
(PUP-2882) Correct acceptance test for single version module upgrade

Before this commit, the acceptance test for upgrading a module which
only has one version was expecting old error messages. This commit
corrects the acceptance test to expect the new error message.
Merge pull request #2901 from andersonmills/bug/master/pup2882-acceptance_test_change_for_only_one_module_version

(PUP-2882) Correct acceptance test for single version module upgrade
(doc) Update ssh keys docs to note that they are not hex
Merge pull request #2902 from jpartlow/pull-2894

(doc) Update ssh keys docs to note that they are not hex
(docs) Clarify documentation about --logdest, puppetdlog, masterlog, and masterhttplog
Merge pull request #2887 from Yggdrasil/patch-1

(doc) Fixes simple typo in 'parser' section
Merge pull request #2891 from nfagerlund/docs_apply_logdest

(docs) Clarify documentation about --logdest, puppetdlog, masterlog, and...
Merge branch 'master' of https://github.com/puppetlabs/puppet