This patch catches exceptions in DDLProc, DMLProc and ExeMgr which could
potentially happen during startup. Logging them instead of silently
ignoring them (or crashing in ExeMgr).
This does the following:
* Switch resource manager to a singleton which reduces the amount of
times the XML data is scanned and objects allocated.
* Make the I_S tables use the FE implementation of the system catalog
* Make the I_S.columnstore_columns table use the RID list cache
* Make the extentmap pre-allocate a vector instead of many small allocs
