Patchers nitpick

- Try block removed in AssortedTweak_NoLightFlicker

  See commit's https://github.com/wrye-bash/wrye-bash/commit/3aa3c941b2de6d751f71e50613ba20ac14f477e8 comments for details

- Removed TODO

  See: https://github.com/wrye-bash/wrye-bash/commit/730eff02c9af16f1c88443d25b2cef89b39993ee#diff-1f37627f4d9ab352fab2c141c307ea09L23537 comments

- self.SEFF = MGEFCode('SEFF') explanation:
  https://github.com/wrye-bash/wrye-bash/commit/730eff02c9af16f1c88443d25b2cef89b39993ee#diff-1f37627f4d9ab352fab2c141c307ea09L23537
Ripped constants from basher