User visible changes in the firmware version 3.5.7 since version 3.5.6.

                             Highlights.

1. Rather rarely, absence of raw CNAV data in "gd" messages for some
   particular satellite(s) has been noticed. Fixed.

2. WLAN: fix AP selection to select one with best RSSI.

3. TYRANT: implement bit#4 in PRTT option to allow for RS232 port.

4. Bug processing ephemerides provided by RTCM3 messages has been
   fixed.

5. Bug has been fixed - empty [TR] messages.

6. TRIUMPH1,TRE_XXX,TR_VS: fixed problem with newer SDRAM chips.


                      More Detailed Description
                (refer to GREIS for even more details)


                             1. Messages.

No changes.

                             2. Parameters.

No changes.

                             3. Options.

3.1 New bit #4 for PRTT option for TYRANT.

In TYRANT, bit#3 was ignored and Serial D was always set to RS422
mode. To allow to set Serial D into RS232 mode and keep backward
compatibility, new bit#4 was implemented.

PRTT -  Port type. Enable RS422 mode by port. This is a bit-field
        option:

bit#0 - enable RS422 on Serial A.
bit#1 - enable RS422 on Serial B.
bit#2 - enable RS422 on Serial C.
bit#3 - enable RS422 on Serial D.
bit#4 - enable decoding of bit#3 on TYRANT

If bit#4 is not set for TYRANT, bit#3 is ignored and port D is always
set into RS422 mode.


                             4. Commands.

No changes.

<END>
