Check for handling of exotic characters

[phihag]

Add a check that the application in question can handle exotic characters and does not break down. In particular, this includes

• [x] Quotes (", ')
• [x] Brackets (<{[()]}>)
• [x] Ampersands and pipe symbols (&|)
• [x] Characters outside of the BMP, such as this one
• [ ] The NUL character
• [ ] Byte sequences that are not valid UTF-8

[rliebig]

The CLRF-Sequence should also be tested by this attacker.

[rliebig]

Ignore my last comment, CLRF deserves a own attacker.