Solves problem with oracle long and long raw datatypes.

see http://docs.oracle.com/html/A96160_01/features.htm#1048395
added test to demonstrate parallel connection error before accepting PR to fix it
Merge pull request #16 from dolgof/master

Fix: An error occurred while parallel accessing to some variables in async methods
Revert previous PR
Merge pull request #17 from pjlammertyn/master

Solves problem with oracle long and long raw datatypes.
1.1.1
credit for that last update
Threadsafe wrapper for DataBase class added