Exceptions - more tests
Exceptions improvements/integration

1) dump_error moved to Exceptions.pm
2) exception_message implemented
3) Exceptions.pm integrated to main program
4) Utils.pm cleaned from old code
5) Exception tests improved
6) Existing tests fixed
TODO added
Exceptions - improve Journal exceptions with new Exceptions API
Remove hexstring format from exception_message, to avoid cyclic dependencies

Use instead hex_dump_string directly when raising exception
open_file exceptions implemented + test + some fixes