georaster - make regular table and secure file a default for RDT

[ilucena]

For newer version of Oracle, the GeoRaster raster data table (RDT) can be a "regular table" as long as it has the necessary columns with the correct types. Oracle 10 and older only accept RDT as "object table".

The GeoRaster driver only create the RDT if that doesn't exist yet. It is very usual that users will create table before loading large amount of images. The same applies for the GeoRaster table. Users can create it previously or define it with the create-option DESCRIPTION.

Until now the GeoRaster driver always create RDT as "object tables". But since the "regular table" are more flexible we should make it a default and add a create-option for users to request RDT as "object table". Again, if the table doesn't exist yet.

Also about RDT, for newer version of Oracle we should define that by default the LOB column "rasterBlock" is stored as "secure file", since that is more efficient. We don't need to add a create-option for that. If users don't want "secure file", they should create the RDT previously.

[ilucena]

Implemented on r26102 on trunk.

The create-option for object table is OBJECTTABLE=TRUE, the default is FALSE.

I haven't test it on Oracle 10 yet, but I will do it shortly.