Handling of property value/-datatype

Currently we have three datatypes for a property value:

• value (varchar)
• clobvalue (longtext)
• blobvalue (longblob)

But for the defaultValue only varchar is possible.

Depending on the property also only one of the datatypes is possible (in most cases varchar).
For example, the value of site property documentDir must be varchar even a longtext could be possible and/or is set.

So one optimisation could be to always use longtext for text values. So we end up with only two clob / blob datatypes.