Relation.where with no args can be chained with not, like, and not_like

examples:

  Model.where.not field: nil
  #=> "SELECT * FROM models WHERE field IS NOT NULL

  Model.where.like name: 'Jeremy%'
  #=> "SELECT * FROM models WHERE name LIKE 'Jeremy%'

this feature was originally suggested by Jeremy Kemper https://github.com/rails/rails/pull/5950#issuecomment-5591330

Closes #5950
Use attr_accessor for Rails.{application,cache,logger}
Add periodical-style TOC and navigation to Kindle version of guides
Add metadata to schema_migrations

migrated_at: timestamp when migration run
fingerprint: md5 hash of migration source
name: filename without version or extension
Add migration history to schema.rb dump
style cleanup
add a notice about loading assets in production mode
Merge pull request #120 from tonytonyjan/patch

add a notice about loading assets in production mode
Correct bad English
Define a generator before referring to it
Replace comments' non-breaking spaces with spaces

Sometimes, on Mac OS X, programmers accidentally press Option+Space
rather than just Space and don’t see the difference. The problem is
that Option+Space writes a non-breaking space (0XA0) rather than a
normal space (0x20).

This commit removes all the non-breaking spaces inadvertently
introduced in the comments of the code.
Adding filter capability to ActionController logs
Merge pull request #8421 from claudiob/remove_unicode_blanks

Replace comments' non-breaking spaces with spaces [ci skip]
Merge pull request #8404 from freegenie/filter_redirects
Extract method refactoring in ActionDispatch::Routing::SingletonResource.
Merge pull request #8412 from JoeyButler/action_dispatch_routing_mapper_refactoring

Extract method refactoring.
Allow fragment cache to accept :if and :unless options

[Stephen Ausman + Fabrizio Regini]
Merge pull request #8371 from freegenie/5396-conditional-fragment-caching

Allow fragment cache to accept :if and :unless options.

Closes #5396
silence warning: possibly useless use of a constant in void context
Merge pull request #8424 from kennyj/tiny_fixes_20121206

fix warning: possibly useless use of a constant in void context