i18n for will_paginate helper

fixes CNVS-11947

the will_paginate actionview helper in will_paginate 3+ uses direct
calls to the I18n.translate method. they didn't match the current
signature (english default as second argument) for our customized
I18n.translate flow. so we adjust our version to allow the (key,
options) call signature as well as (key, default, options). the default
can be specified in the options with the :default key if it's not
hard-coded into the config/locales/en.yml file.

however, will_paginate is bad at actually passing the default to
I18n.translate anyways. fortunately, it provides an en.yml for its
translations, so we just need to make sure to not automatically
view-scope its translate calls.

test-plan:
 - running rails3, having more than one page's worth of error reports,
   load /error_reports; pagination should not show code or I18n errors

Change-Id: Ib98c566f0823e016f823dbec550260eff18abf98
Reviewed-on: https://gerrit.instructure.com/33707
Reviewed-by: Jon Jensen <jon@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Jacob Fugal <jacob@instructure.com>