Fix circuit opening on ubuntu 12.04

On some systems, apparently .circuit files get opened by ktechlab as text files. These errors are apparently mimetype configuration problems. This pull request implements _test_ inside ktechlab for detecting broken configurations and showing debug information.

Circuits get opened as simple text when there is more or less than 1 .circuit mimetype (application/x-circuit) definition on the system. Partially it is a KDE bug (or feature?), because it does not discard duplicate mimetype entries, and it does not deal correctly with broken mimetype database configurations.

Currently there is no automated way of fixing the broken mimetype configurations. One could be created, by seaching in the filetypes definitions and discarding databases with additionally define the circuit mime type. For now i did not implement this logic, because it will cause problems anyway (some filetypes get "lost" by ktechlab). If needed, the simple-setup.sh script could be extended with more robust mimetype database handling.

For more context see also bug #10 .

Please review this code, and give some feedback on the implementation.