Emulated scrollable cursor temp files in DBTEMP

Directory of scrollable cursor data storage can be defined with DBTEMP.

On UNIX™ platforms, starting with 2.30, the temporary files for emulated scrollable cursors will be created in the directory defined by the DBTEMP environment variable when defined, otherwise TMPDIR, TEMP or TMP will be used. Using DBTEMP for database files conforms to DBTEMP usage for temporary files of TEXT and BYTE data storage.