Rails.logger should have level specified by config.log_level. 

Fix bug when log level of Rails.logger (which was set via config.logger) does not match the    config.log_level.
fix tests
update guide to reflect default HMAC SHA1 in MessageVerifier used in SignedCookieStore [ci skip]
remove language about configuring digest method [ci skip]
Minor optimization and code cleanup in query_methods.

- Use symbols rather than strings where possible to avoid extra object construction
- Use destructive methods where possible to avoid extra object construction
- Use array union rather than concat followed by uniq
- Use shorthand block syntax where possible
- Use consistent multiline block styles, method names, method parenteses style, and spacing
Updated the guide to say that the localisation file for validation messages is in activemodel, not activerecord
[Fixes #11734]Correct Association Basics Guide on has_and_belongs_to_many[ci skip]

Done the following changes:
 1. Replace uniq call in example with autosave as uniq is not supported
 on has_and_belongs_to_many
 2. Add :readonly option to list of supported call as per
 [EdgeApi](http://edgeapi.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_and_belongs_to_many)
Changing the def self.table_name to self.table_name in the column_name.rb
Merge pull request #11740 from Karunakar/self_table

Changing the def self.table_name to self.table_name in the column_name.r...
Merge pull request #11738 from gaurish/guides-association-basics-fix

[Fixes #11734]Correct Association Basics Guide on has_and_belongs_to_many
Merge pull request #11600 from jasiek/master

Removed an unnecessary loop - it kills performance on large texts.
Add note that you must be in the rails app directory when starting up the server.

This is a response to issue #11731 and is a common mistake for people
newer to rails that try forget to cd into the new rails app after
running rails new.
Merge pull request #11733 from iainbeeston/master

i18n guide update: corrected reference to activerecord to instead reference activemodel
Merge pull request #11747 from bradly/guides_getting_started_fix

Add note that you must be in the rails app when starting the server
No need to abbreviate application

[ci skip]
:scissors:

[ci skip]
Remove "Using Action View outside of Rails" section from AV overview guide

The section was clearly wrong and was just an example about how to use ActiveSupport helpers in Rack/Sinatra
Fix unused variable warning

We need to call `in_time_zone` to test that it isn't modifying the receiver
but since the variable isn't used it raises a warning so add an assertion
to make Ruby think it's being used.
No need to use blocks here
Added to 'Security' section; especially reference to 'Ruby on Rails Security Guide'. [ci skip]