* table_exists? scoped by schema search path unless schema is explicitly named. Added tests and doc to clarify the behaviour
* extract_schema_and_table tests and implementation extended to cover all cases
* primary_key does not ignore schema information
* add current_schema and schema_exists? methods
* more robust table referencing in insert_sql and sql_for_insert methods

Revert "[activerecord][postgresql] verify if table has a schema(not public)". This caused a test breakage. See #1410 for details.

This reverts commit c44418ea.

pg_namespace has not been used since this commit 29b0707f

Applied Patch from https://rails.lighthouseapp.com/projects/8994/tickets/5577-suport-from-tsvector-data-type-in-postgresql

fetch result row arrays from pg in C and return early if there are no money or binary columns. ❤

Fix test_load_save in test/cases/binary_test.rb (thanks @tenderlove for actually working out how to fix it)