various fixes to darcs conversion script
1. removed files were missed
2. hidden files in top directory were not added/removed correctly
3. suppressed spurious warning on adding new files.
4. hg changeset now checked in with original author and date
5. __file__ not supported by pdb.py
abort: impossible time zone offset: 4444444
transaction abort!
rollback completed
abort: invalid date: '1\t15.1'
transaction abort!
rollback completed
abort: invalid date: 'foo bar'
transaction abort!
rollback completed
abort: invalid date: ' 1 4444'
transaction abort!
rollback completed
abort: date exceeds 32 bits: 111111111111
transaction abort!
rollback completed
abort: No such file or directory: .../test/bar