Updates to remove c++ 11 code, remove prepared statements properly, clea...

...n-up locking on sessionHandle

Per Alek’s observations the following changes were made:
1) Update components and Makefile to include PostgreSQL code and test
suite
2) remove C++11 code references

Additional changes made to adhere to PostgreSQL libpq requirements

1) Remove Prepared statements when statements go out of scope.  This is
complicated by transactions such that prepared statements created
during a transaction must continue to exist as prepared statements.
Code updated to delete prepared statements at the proper time.  CLIENTS
ARE REQUIRED TO ISSIE Poco::Data API CALLS FOR TRANSACTION SUPPORT AND
NOT SEND BEGIN, COMMIT OR ROLLBACK STATEMENTS DIRECTLY.

Also update SessionHandle.cpp code to make better use of locking where
public methods request the lock and private methods do not.  This is to
prevent deadlock conditions from occurring