Add various corrections following review
Add various corrections following review

-.Do not remove ge- in words starting with gelt- or gebn-
- Replace -tn, -te, -ter with -t no matter how early in the word
   (if before R1)
- Remove Ayin also in -et, -etn, -ets, -ete, -eter
- Always remove -endik if after R1

snowballstem/snowball,snowballstem/snowball,snowballstem/snowball,snowballstem/snowball,snowballstem/snowball,snowballstem/snowball,snowballstem/snowball,snowballstem/snowball