Fix AM testcase break with mail 2.5.4. It seems that AM's testcase was wrong.
Merge pull request #10646 from kennyj/fix_am_20130517

Fix ActionMailer testcase break with mail 2.5.4.
No need CHANGELOG entry for a test fix

[ci skip]
Add has_named_route? to the mapper API
Spelling correction in Upgrading Guide

Fixes spelling of 'erratta' to 'errata'
Merge pull request #10697 from zhubert/patch-1

Spelling correction in Upgrading Guide [ci skip]
pass where values to the helper function rather than rely on internal state
save the where values in variables so we don't need to look them up all
the time
change method name to reflect what it actually does.
eliminate some conditionals