- NEW: added initial UltrasonicRanging version
- FIX: UltrasonicSensor dtor: delete NewPing after detaching from Ranging context.
- FIX: UltrasonicRanging ctor: using Timer::IS_RECURRING when creating the recurring m_triggerTimer.
- FIX: UltrasonicSensor: introducing DISTANCE_LIMIT_EXCEEDED distance flag value
- FIX: UltrasonicSensorHCSR04: renamed s_defaultMaxDistance to DEFAULT_MAX_DIST, made it available publicly

Signed-off-by: dniklaus <dieter.niklaus@gmx.net>
- FIX: UltrasonicSensor::echoCheck(): removed faulty else branch in check_timer() condition.

Signed-off-by: dniklaus <dieter.niklaus@gmx.net>
- CHG: using simplified Timer API

Signed-off-by: Dieter Niklaus <dieter.niklaus@gmx.net>
- CHG: using simplified Timer API

Signed-off-by: Dieter Niklaus <dieter.niklaus@gmx.net>
Merge branch 'master' of https://code.google.com/p/arduino-driver-ultrasonicranging