TestInsight does not handle non ansi properly

[Stefan Glienke]

To reproduce:

• put some non ansi characters (like the german ä, ö or ü) into the unit with a testcase
• execute tests
• try to navigate to the test by double clicking -> error

[Stefan Glienke]

handle editor buffer properly (fixed #46)

→ <<cset d4a36631f83f>>