Fix build on Qt4.

There is not QFileDevice in Qt4. The Permissions enum is inside QFile
class. In Qt5 QFile inherits from QFileDevice, so we can use QFile::
scope here as well.
Adapt testGetShouldFail.

GET requests are rather file download stuff than SOAP stuff, so we
report errors with HTTP errors rather than SOAP faults.
Merge pull request #33 from krnowak/file-download-hang-test-fix

File download hang test fix