silences "possibly useless use of :: in void context" warnings

The AS utility silence_warnings does not really silence this
one, because it is issued at parse-time. It seemed to in
some places because the constant was the only expression in
the block and therefore it was its return value, that could
potentially be used by silence_warnings are return value of
the yield call.

To bypass the warning we assign to a variable. The chosen
variable is "_" because it is special-cased in parse.c not
to issue an "assigned but unused variable" warning in turn.
minor grammar fix
Merge pull request #8604 from zoltankiss/minor_fixes

minor grammar fix
Merge pull request #8592 from rafaelfranca/warning_fix

Remove warning of intance variable not initialized
ActiveSupport::BufferedLogger can be subclassed
Merge pull request #8607 from senny/8576_cant_inherit_from_deprecated_buffered_logger

ActiveSupport::BufferedLogger can be subclassed
deprecation warning when BufferedLogger is instantiated
replace AS::BufferedLogger doc mentions with AS::Logger
Merge pull request #8609 from senny/buffered_logger_documentation

replace AS::BufferedLogger doc mentions with AS::Logger
Merge pull request #8608 from senny/8576_cant_inherit_from_deprecated_buffered_logger

deprecation warning when BufferedLogger is instantiated
validate :on option on after_commit and after_rollback callbacks
Revert "Ignore /bin on new apps" -- given the move to default binstubs, we want you to check those in!

This reverts commit 35c554f0bf518e1068e79002a462c3deba649e9b.
more descriptive return parameters
Merge pull request #8600 from shime/patch-1

more descriptive return parameters
We need to check explictly that env['action_dispatch.show_exceptions']
is false.

If it is nil we can't raise the exception
Merge pull request #5100 from paukul/validate_on_condition_on_transaction_callbacks

Validate :on option on after_commit and after_rollback callbacks
quote column names in generated fixture files
Fix CHANGELOG style [ci skip]
Merge pull request #8616 from senny/8612_respect_yaml_keywords

quote column names in generated fixture files
Consistent use of single and double quotes