New TinySoftPwm library: a tiny optimized software PWM manager

Mainly designed for Digispark
added TinyPinChange_DisablePin(), TinyPinChangeDemo example and fixed keywords.txt
SoftSerial: Added Tx/Rx capabilities on the same pin and added Digi_1io_SerialDbg example

Allows bi-directional debug on a single pin with Digispark
RcSeq: only needed capability are configurable in RcSeq.h; added DigiRcSeqZodiac example

More usable with the low resources of the Digispark
Fixed TinyPinChange.h include path in SoftRcPulseOut.h
SoftRcPulseOut: Added Usb2Servos example to command servos through USB
Size optimized VirtualWire library with capability to call external function in ISR

Optimized for Digispark
HW PWM up to 64.5KHz@16.5MHz without breaking micros(), millis() and DigiUSB

Nice to control brushed motors without audible noise
Restore timer default predivisor after high speed PWM support addition

Default timer predivisor for ms
Merge pull request #5 from RC-Navy/master

Some enhancement for Digispark