Moved options parse checks to main().
Moved options parse checks to main().

Would like to add a smoke test for this module, and add some
charaterization tests for the sample filter generation.  Moving this code
to main() ensures that the same options checks are done during testing.

rarcotvmw/capirca,google/capirca,google/capirca,google/capirca,ryantierney513/capirca,ryantierney513/capirca,rarcotvmw/capirca,ryantierney513/capirca,google/capirca,rarcotvmw/capirca,sneakywombat/capirca,sneakywombat/capirca,pettai/capirca,pettai/capirca,sneakywombat/capirca