Includes call to pre-processor and post-processor scripts in file_space_account.

It is added in $CONFIG_DIR/file_space (usually /var/opt/openit/etc/file_space):

GLOBAL_PREPROCESSOR: <pre-processor script>
GLOBAL_POSTPROCESSOR: <post-processor script>

The post-processor script will only be called on successful completion of collection job.

This patch will reset access time of the directories that are entered through disk scan.

Change code that goes through the directory structure so that it
no longer reads entire directory cataloges into memory at once.
This should reduce the memory usage of file_space_account when
encountering direcories whith a large amount of files.