Remove ActionController::RaiseActionExceptions.

The latest modification to the code was done in https://github.com/rails/rails/commit/5e3517ea. In Rails 3.2,
`ActionController#rescue_action` was deprecated and `rescue_action_without_handler` is no longer being used.
Merge pull request #16419 from tgxworld/remove_legacy_code

Remove ActionController::RaiseActionExceptions.
Merge pull request #16412 from yevhene/master

Fix in has_secure_password for passwords containing only spaces.
Fix typo [ci skip]
Tables existence check query is executed in large quantities

When Rails starts, tables existence check query is executed
number of models.
In case of mysql,

    SHOW TABLES LIKE 'table1';
    SHOW TABLES LIKE 'table2';
    SHOW TABLES LIKE 'table3';
    ...
    SHOW TABLES LIKE 'table999';

Add process to get the names of all tables by one query.
Fix spelling.
Merge pull request #16422 from tgxworld/fix_spelling

Closes #16422
change to empty? from blank?
Merge pull request #16421 from tsukasaoishi/prevant_manycall_showtables

Tables existence check query is executed in large quantities
use the uri parser so that newer version of Ruby work
remove dead file_watcher code
Merge pull request #16424 from gregors/remove_dead_code

remove dead file_watcher code
defer running after_config hooks until after the object is allocated
add a new constructor that runs load hooks
need to call super
Stop using padding in the generated Gemfile -- it looks shit
Merge branch 'master' of github.com:rails/rails
Pull spring gem entry into the Gemfile template instead of gemfile_entries so it can be grouped with the other development tools
Merge pull request #16384 from tomkadwill/improved_create_documentation

[ci skip] Added +object+ and +attributes+ to create! description for rdoc
Rephrase how we explain RecordInvalid exception in the context of
`#create!` regarding validations in contrast to the behavior of
`#create`. Also describe creating multiple objects using an array of
hashes as the +attributes+ parameter. [ci skip] /cc #16384