Improve Util::displayString

Render objects without objectName like this:
"ClassName[this=0xdeadbeef]" instead of "0xdeadbeef (ClassName)".

Reasoning: The pointer address is mostly meaningless when looking
through object instances, the class name has more value to us.

This also fixes some representational issues in KDSME
Merge pull request #91 from krf/improve-util-displaystring

Improve Util::displayString

ACK'ed by Volker