Add a skeleton for the Qt TUIO plugin.

This skeleton builds a generic Qt plugin that will generate touch
events.
Implement the TuioTouch plugin.

Generate Qt touch events from the TUIO stream.

The TUIO sampling rate is 10 milliseconds because the amout of lag feels "right." Bob
also informed me that Perceptive Pixel uses a timeout of 10 ms.
Add a graphics view demo to test the TUIO touch plugin.
Reuse the allocated memory for storing the address pattern and type string.

The "parse_message" function is called repeated. It is beneficial to reuse the memory used
to store the address pattern and the type string.
Don't allocate unneeded memory to get a string tag.

Return the raw const char pointer because OSC provides c-style strings within the encoding.
Install the Qt plugin into the correct plugin directory for use by Qt programs.

This is basic functionality; would be nice if it picked up the Qt directory as the default prefix.
Guess the default prefix based on the location of the used qmake.

Try to install the plugin along side the rest of the Qt toolchain.