generate desired sptimes_flat filename

edited sprintf usage
added new variable 'standardArea' (always V1)

Variable 'standardArea' refers to area from which representative
standard sessions are selected, and is always V1. Avoids confusion
between 1. area of session being processed and 2. area of session being
used as the standard, with which (1) is compared.
fix for sptimes_flat filename
use variable 'standardArea' to retrieve data
set target range for spontaneous activity