Use footprint in seeding

[Schpidi]

Using the exact footprint instead of a bouding box speeds up the seeding. In the example below the time needed was 1m49s instead of 2m17s or a reduction of about 20%.

mapcache_seed -c /var/www/cache/seed_mapcache.xml -t TEST_MER_FRS -g WGS84 -e 8.478450,32.190250,25.410150,46.268645 -n 1 -z 0,8 -D TIME=2012-10-02T09:20:00Z/2012-10-02T09:20:00Z -m seed -f -M 8,8

mapcache_seed -c /var/www/cache/seed_mapcache.xml -t TEST_MER_FRS -g WGS84 -n 1 -z 0,8 -D TIME=2012-10-02T09:20:00Z/2012-10-02T09:20:00Z -m seed -f -M 8,8 -d PG:"dbname='...' user='...' password='...'" -l coverages_eometadatarecord -w id=18