release v.05

Features:

• imported awesome @egzumer spectrum scan range
• ENABLE_ULTRA_LOW_POWER_TX Makefile flag (disabled by default) based on @egzumer tests allowing to transmit with ultra low power for debug/testing purposes

Improvements:

• increased spectrum scan range blacklist size from 15 to 200 as it improves signal hunting in noisy environments, also helps to hunt smaller signals better by allowing lower rssi trigger over wider range of frequencies

Fixes:

• fixed spectrum scan range visual bug (egzumer#314)
• proper setting of RX_OFFSET in EEPROM (read, then write approach)