Refactored the single and multi segment processing.

The script now only gatheres one array, and the csv creation is done
within a separate method.

Tested-by: Gordon Thomson <gordon@pccl.co.uk> [Ubuntu 11.10, MRI 1.8.7]
Signed-off-by: Gordon Thomson <gordon@pccl.co.uk>
Script handles if scans are always on a specific day of the week.

The option exists to specify which day of the week scans are performed
on.
This gives more accurate results for date selection.

Tested-by: Gordon Thomson <gordon@pccl.co.uk> [Ubuntu 11.10, MRI 1.8.7]
Signed-off-by: Gordon Thomson <gordon@pccl.co.uk>
Add prompt for NVt downloading, add formatting.

Tested-by: Gordon Thomson <gordon@pccl.co.uk> [Ubuntu 11.10, MRI 1.8.7]
Signed-off-by: Gordon Thomson <gordon@pccl.co.uk>