Firmware and Software Update on Retevis RB17P GMRS Radio

This month, we do a update for Retevis RB17P GMRS radio according to our customer feedback. 

Firmware Update Changelog:

1. Add menu "T-CDC, R-CDC", VOX and VOX delay, Scan Mode:CO,TO,SE.

2.Frequency involved 467.5625，467.6125，467.6625，467.7125，467.5875，467.6375，467.6875, will be fixed to nonadjustable Narrow bandwidth and Low Power. Other frequencies will all default to Wide bandwidth and High power.

3. Cancel preset CTCSS/DCS tones: Find the menu 23 Reset, add CH QT/DCS. it will cancel all the preset CTCSS/DCS tones.

Software Update Changelog:

1. Frequency involved 467.5625，467.6125，467.6625，467.7125，467.5875，467.6375，467.6875, will be fixed to nonadjustable Narrow bandwidth and Low Power. Other frequencies will all default to Wide bandwidth and High power.

2. Allow to edit the channel name.

3. Add the menu VOX delay time.