two phase support for oracle

[Mike Bayer]

see Anthony Tuniga's suggestion at http://permalink.gmane.org/gmane.comp.python.db.cx-oracle/940 for guidance.

[Former user]

there's a bug in file "dialects/oracle/cx_oracle.py" in function "create_xid": random.randint(...) is used but the module "random" is not imported; import it at function level should be enought to fix this issue

[Mike Bayer]

fixed the random import in 4f00f200724815f953a6f8d0527c1c78015afe6f.

[Mike Bayer]

two phase is actually working in oracle, we need the patch in #2611 to make it complete, however there are serious caveats with cx_oracle and two phase, in that the connection can only be used for two phase once it is used that way the first time. there's no solution to this now as anthony is not responding.