Adding pgbouncer transaction patch.

Originally from http://treehou.se/~omar/postgresql-jdbc-8.4-701-pgbouncer_txn.patch
Markdown version of the README
added Loglevel.OFF to complete the settings
Merge pull request #41 from davecramer/master

Added constant for turning logging OFF
avoid NullPointerException from Derrik Hudson on User Defined Types
Merge pull request #42 from davecramer/master

Avoid NPE on user defined types which have a value of null provided by Derrick Hudson
removed compile error with double ,
Merge pull request #43 from davecramer/master

fix compile error
Merge pull request #40 from lordnelson/doc_changes

Markdown version of the README file
Support for JDBC4 isWrapperFor & unwrap methods
Added unit test for wrapper functions
Change default password to 'test'

./org/postgresql/test/README says the default password for unit tests is 'test',
but the default was actually 'password'
Merge pull request #44 from fathomdb/support_wrappers

Support for JDBC4 isWrapperFor & unwrap methods
Merge pull request #45 from fathomdb/fix_default_password

Change default password to 'test'
fix a simple miss in getPropertyInfo()
Merge pull request #48 from ChenHuajun/master

Fix a simple mistake in Driver.getPropertyInfo()
Remove plaintext README in favor of Markdown version.

Having two copies is just going to invite drift.
Lookup correct array delimiter in Connection.createArrayOf.

The old code had hardcoded a comma, but that's not true for all
datatypes.

Identification and fix by sumo in pull request #49, testcase by me.
Consider search_path when resolving type names to OIDs

In case when types with the same name existed in several schemas,
TypeInfoCache did not consider the current search_path and was choosing
an OID of a type not deterministically. These change will make
the type from the current schema to be chosen. Also this change remains
backwards compatible with the previous implementation, still being anble
to find a type, that is not included into the current search_path.

Provided test fails now, as it does not TypeInfoCache
directly. So more work is to be done to make this test work.
Test is checking search_path usage dirctly on TypeInfo methods