Allow global override of default STI inheritance column

This change fixes a bug by which 3.2-STABLE users can't globally override the default STI inheritance column with `ActiveRecord::Base.inheritance_column = 'some_column'`. 3.2-STABLE users are forced to use a deprecated method or monkey patch it otherwise.

Test case written by tkhr <takehiro0740@gmail.com>.
build fix, fall back to old hash syntax
Merge pull request #11019 from tkhr/test_case_for_issue_10393

Add test case for issue #10393 and fix warning message
Backport rails/rails-perftest#2 to fix rake test:benchmark
clear ARGV to prevent mintest autorun errors:

Minitest expects the first argument in `ARGV` to be the path to a test file.
Because `rails benchmarker` and `rails profiler` define an on-the-fly test-case,
using the first `ARGV` to pass the code to execute this results in:

```
/Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:167:in `block in non_options': file not found: 1000.times{"a string"} (ArgumentError)
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:146:in `map!'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:146:in `non_options'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:207:in `non_options'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:52:in `process_args'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/minitest/unit.rb:891:in `_run'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/minitest/unit.rb:884:in `run'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:21:in `run'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:326:in `block (2 levels) in autorun'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:27:in `run_once'
	from /Users/senny/.rbenv/versions/1.9.3-p374/lib/ruby/1.9.1/test/unit.rb:325:in `block in autorun'
```

clearing ARGV after defining the test-case solves this issue.
Merge pull request #9173 from senny/backport_perftest_fix

Backport rails/rails-perftest#2 to fix rake test:benchmark
unify duplicate CHANGELOG entry
Incorrectly providing program name the same as log message even when block is not provided.
Merge pull request #8881 from carsonreinke/3-2-stable

3-2-stable ActiveSupport::TaggedLogging logging progname issue
Add missing require
Skip connection url test when the machine is using socket configuration.

The connection url parssing don't accept the socket option
Remove warning of assigned but unused variable
New changelog entries always on the top [ci skip]
Add license to the gemspec
Remove git dependecy
Do not shallow the original exception in exec_cache

when result_error_field is not defined on result raise the original
exception.

Fixes #11260
Retain offset and fraction when using Time.at_with_coercion

The standard Ruby behavior for Time.at is to return the same type of
time when passing an instance of Time as a single argument. Since the
an ActiveSupport::TimeWithZone instance may be a different timezone than
the system timezone and DateTime just understands offsets the best we
can do is to return an instance of Time with the correct offset.

It also maintains the correct fractional second value as well.

Fixes #11350.

Backports:
484253515c0e05760541dc48946361185c9e6904
1b3873730b96035a238dbff7627bd5942e6dc4e7
Return local time for backwards compatibility
Add missing require so that DateTime has the right superclass

If the DateTime core extensions were loaded before the Date core extensions
then you would get a superclass mismatch as DateTime hasn't been defined
yet so it gets set to Object by the acts_like core extension.

Fixes #11206

(cherry picked from commit 78f7d5b652000dbb1a11d34fe370c3fa82de840c)
Preparing for 3.2.14.rc1 release