Currently sequence messages are added to traces as they are
received. Therefore content of traces depends at the time, when
request is issued and data is reported. Sometimes not all sequence
traces are reported, because only first record was received yet and it
overwrote previous full sequence trace.
For example,
```
$GPGSV,3,1,12,01,35,282,,02,68,264,,03,02,243,,08,35,206,,1*68
$GPGSV,3,2,12,10,46,074,,14,16,312,,17,,,,22,16,327,,1*53
$GPGSV,3,3,12,23,07,068,,24,15,030,,27,14,181,,32,51,120,,1*60
$GLGSV,2,1,08,82,25,135,,76,11,029,,75,21,334,,69,11,201,,1*7A
```
one GSV sentence is missing and second later full sequence is
reported
```
$GPGSV,3,1,12,01,35,282,,02,68,264,,03,02,243,,08,35,206,,1*68
$GPGSV,3,2,12,10,46,074,,14,16,312,,17,,,,22,16,327,,1*53
$GPGSV,3,3,12,23,07,068,,24,15,030,,27,14,181,,32,51,120,,1*60
$GLGSV,2,1,08,82,25,135,,76,11,029,,75,21,334,,69,11,201,,1*7A
$GLGSV,2,2,08,84,40,306,,83,79,161,,67,56,056,,68,58,177,,1*7D
```
Therefore client software reports different number of visible
satellites.
Usually sequence sentences are reported consequently in NMEA
stream. Let's cache and join sequence sentences until new trace type
is received. In that case full sequence always overrides
previous full sequence.
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Andrey Skvortsov
f7da97989b