PURPOSE: Apply eclipse corrections (when present) to 3D data structures within thm_part_moments.pro ARGUMENTS: dat: Valid 3D data structure KEYWORDS: domega: Array of weights used inside the Wind routines to calculate vector and tensore components. This array should be set to 0 if a correction is being applied or if a correction was applied on the last loop. eclipse: Flag used by this routine to determine when an ecplise starts or ends (assists output messages). Should be set to 1 at the start of an eclipse and 0 at the end. previous: Stores the delta phi value from the last time through the loop. Helps determine when domega should be zeroed. NOTES: