Add a decorator to prevent Exceptions (to prevent segfaults).
Prevent exceptions in NetworkManager::createRequest.
Remove exception handling code for qutescheme.

The exceptions now get handled by @prevent_exceptions on the createRequest
method of the NetworkManager, causing the exception handler to pop up properly.
Update BUGS/TODO
scripts: Add more pages to segfault_test
scripts: Annotate pages with bug reports in segfault_test