remfin: Make removing of fins more modular.
- spot/twaalgos/remfin.cc: Refactore remove_fin implementation. Enable filtering of strategies used for fin removing.
- spot/priv/enumflags.hh: Add support for enum flags from brick-types.
- spot/priv/Makefile.am: Add enumflags.hh to make.
- debian/copyright Update copyright with bricks library license.