(doc) Fix a typo in docs for the include function

There is a typo in the documentation for the include function.
This patch merely fixes that typo.
(maint) Banish "configuration parameter"

They are called settings!

Note: Two spec files relied on the wording of an error message I changed.
I revised them to find the new wording.
Merge pull request #2365 from alexharv074/fix_typo_in_include_doco

(doc) Fix a typo in docs for the include function
Merge pull request #2368 from nfagerlund/maint_configuration_parameter

(maint) Banish "configuration parameter"
Merge branch 'master' of https://github.com/puppetlabs/puppet