fixed dates maker test
added simple read test for annotations
added missing input file
added another subtyping test
improved write test
fixed some broken test cases
updated write tests
fixed broken tests
added a test to check that missing type blocks are reported as exceptions of some kind
updated date write tests
fixed some write related tests and removed debug code
provided function in common test for the creation of temporary files; fixed #6
improved subtypes read test
fixed subtypes write test
added some regression tests and updated error messages
added append tests for date