handle files that overlap metric day in archive

[areeda]

detect when a trigger file overlaps day boundary and split it
detect when a trigger file overlaps one in the archive but is not a subset of what is already in the archive

[areeda]

The problem has been resolved for new jobs but this issue remains open because trigger files with the issue exist.
The problem exists when an interval starts near a boundary eg: 1349899999 and goes for say an hour. If gwtrigfind looks for triggers starting after the [metric] day change it will not find this file.