Remove current_adapter? from test_sanitize_sql_hash_handles_associations

Because of each adapter implementation differences,
`expected_value` string needed to be handled by each adapter.
This commit removes current_adapter
by using ActiveRecord::ConnectionAdapters::Quoting methods.
dependency ActiveSupport::Deprecation
Merge pull request #10519 from eiel/dependency-core_ext-hash-diff

dependency ActiveSupport::Deprecation
Use ruby's Encoding support for tidy_bytes

The previous implementation was quite slow. This leverages some of the
transcoding abilities built into Ruby 1.9 instead. It is roughly 96%
faster.

The roundtrip through UTF_8_MAC here is because ruby won't let you
transcode from UTF_8 to UTF_8. I chose the closest encoding I could
find as an intermediate.
adding test to demonstrate inconsistencies in the AS::Callbacks api
refactor tests for more points
adding more tests around callback inconsistencies
Merge pull request #10521 from yahonda/sanitize_oracle

Remove current_adapter? from test_sanitize_sql_hash_handles_associations
Merge pull request #10355 from burke/master

Use Ruby's native Encoding functionality to implement `tidy_bytes`
we need to indicate the type of callback