make default value for `:message` on `AM::Errors` explicit.
Adding documentation to the Rails initialization guide. [ci skip]
Removing deprecation message and silencing method.

The deprecation rake task is no longer useful because the deprecated
methods have already been removed.

The method for silencing stderr has been removed since it was only
useful for `rake test:uncommitted` which was deprecated and removed.
Merge pull request #11133 from wangjohn/remove_deprecation_rake_task

Removing deprecation message and silencing method.
Merge pull request #11054 from senny/11048_make_default_value_explicit

make default value for `:message` on `AM::Errors` explicit.
fix grammar, change 'an' to 'a' [ci skip]
Merge pull request #11139 from prathamesh-sonpatki/grammar

fix grammar, change 'an' to 'a' [ci skip]
activerecord/examples/simple.rb use master branch activesupport gem
Merge pull request #11142 from tumayun/use_master_branch_activesupport

activerecord/examples/simple.rb use master branch activesupport gem
Fix punctuation in config templates
Fix documentation for grouped_collection_select [ci skip]
Fix copyright year for actionview [ci skip]
Merge pull request #11144 from kennyj/fix_copyright_year

Fix copyright year for actionview [ci skip]
Removed "to:" from root directive and fixed typo ":to"

`root :to` is invalid syntax
`root to:` is valid, but the generated routes file omits `to:`
Re-remove deprecated API.
Merge pull request #11145 from JeffreyRodriguez/rails_4_root_directive_updates_and_fixes

Removed "to:" from root directive and fixed typo ":to"
Merge pull request #11146 from kennyj/re-remove-deprecated-api

Re-remove deprecated API.
Merge pull request #11141 from keydunov/master

Fix documentation for grouped_collection_select
Remove passing the prompt to grouped_options_for_select as an argument, because it was deprecated.
Merge pull request #11147 from kennyj/remove_prompt_argument_was_deprecated

Remove passing the prompt to grouped_options_for_select as an argument, because it was deprecated.