[autotests] tst_qfilesystemwatcher fails too often in CI

The tst_qfilesystemwatcher autotest has failed 10 times in CI between April 9. to April 29., 2013, and ranks as one of the top most failing test in that time frame. It seems likely that the test needs fixing.

Most common failure: tst_QFileSystemWatcher::watchFileAndItsDirectory(native backend) Compared values are not the same

See more info in the test results:
http://testresults.qt-project.org/ci/QtBase_dev_Integration/build_00794/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_dev_Integration/build_00797/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00901/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00908/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00933/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00936/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00967/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_stable_Integration/build_00979/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_dev_Integration/build_00834/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz
http://testresults.qt-project.org/ci/QtBase_dev_Integration/build_00853/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz