Remove dom4 folder.

Submitted in https://github.com/w3c/web-platform-tests/pull/613.
Remove tests for WebSQL.
Remove File API tests that have been submitted.

Submitted in https://github.com/w3c/web-platform-tests/pull/55.
Remove tests for FileError.

It was removed from the spec between 2010-10-26 and 2011-10-20. I submitted a
negative test at https://github.com/w3c/web-platform-tests/pull/614.
Also remove tests for FileError and FileException in workers.
Merge pull request #4 from Ms2ger/FileError

Remove tests for FileError.
Merge pull request #3 from Ms2ger/file-api-th

Remove File API tests that have been submitted.
Merge pull request #2 from Ms2ger/websql

Remove tests for WebSQL.
Merge pull request #1 from Ms2ger/contentType

Remove dom4 folder.