[*] Removed all the debugging stuff.
[*] Replaced pointer with reference in finishedMeasure() method signature - it makes using this method more convenient.
[+] Added URM_USE_PORTS_DIRECTLY directive, that makes URMSensor class to (surprisingly!) work directly with I/O port registers instead of using digitalRead() and digitalWrite() functions. It would save about 5-10 us when running refreshState() and finishedMeasure(), but it also would slightly increase RAM usage and make the code less portable. This feature is enabled by default; feel free to disable it if you're going to run this library on Arduino Due, or if you'll find any bugs.
Modified the example demonstrating work in synchronous mode.
Added keywords.txt, removed unused URMErrorCodes enum from URMSensor.h.