SeedingData: tips can not be seeds

This patch removes most of the false seeds.

2.6M Seeds-1.100nt.dat
1.3M Seeds-2.100nt.dat
128K Seeds-3.100nt.dat  *****

Remaining false seeds are high coverage seeds.

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>