Support for String and Number items in pilight binding

This update for the pilight bindings adds support for getting string and number values from pilight, for example temperature readings from a 433Mhz weather station.

[Updated wiki page](https://github.com/idserda/openhab/wiki/pilight-Binding)
With Java >= 5 this replaces all occurrences. Could still replace it with replaceAll() if you think that's clearer.