Import revision 48531 from the v5-34-00 patch branch:
From Sergey:

To guarantee linkage of libclntsh.so library, I add OCIClientVersion() call to TOracleServer class. 
Provided code prints OCI version if gDebug>0.


git-svn-id: https://root.cern.ch/svn/root/trunk@48532 27541ba8-7e3a-0410-8455-c3a389f83636
Precision fix for ComputeNormal. The Z planes are selected in case safetyZ is within 10 times the tolerance (before was 1)


git-svn-id: https://root.cern.ch/svn/root/trunk@48534 27541ba8-7e3a-0410-8455-c3a389f83636