libclosedcaption 1.0.2

Added

• Parsers for the DRCS (1 and 2 bytes), bitmap, geometric graphics and synthesized sound data
  units, and caption_superimpose_new() (text of the superimpose, one message per data unit)
• caption_management_load_unit() to walk through all the data units of a data group
• --units in the example (and make run-example-units) to show those data units
• tests/sintetico-unidades.ts: synthetic stream with one data unit of each type, and tests
  in tests/test-api.c

Changed

• caption_superimpose_new() replaces the global hooks while it runs and restores them after