coding style fixes, GPS initialisation, whitespace

this commit fixes all remaining whitespace issues and makes function
naming not using CamelCase but underscore_spaces.

the rationale will be, that variables have CamelCase spelling and
function names should be underscore_seperated.

also: GPS UART communication was tested and works well. the GPS can be
set to output GPGGA-sentences only, and AlwaysLocate mode can be entered
at will.
add GPS helpers, main structure, more commenting
test blips, add time from GPGGA
util fixes, gps handling OK, NMEA time extraction

utils: there is a new atoi8-function
gps handling: is working completely - waiting for first fix and then
moving the module into alwayslocate-mode, where fixes are only output at
a lower rate (reduces power consumption significantly)
NMEA: time is now also extracted from GPGGA frames
implement RTTY transmission logic, working
add test case to CRC test, for MSP430 compat
implement CRC on MSP430 HW, construct tlm frame

this implements the CRC generation for the payload on the msp430 crc
hardware. this spares the cost of the software implementation.

also, the telemetry frame should now be correctly filled with
information
full working tracker design, CRC implementation OK

this is the first fully working tracker software. it includes some
measures for debugging (LED stuff) and misses the LED measurement stuff

CRC was verified on PC - working nicely!
longer lat/lon, fix buffer lengths
enable watchdog, temp format fix, adc enabled

watchdog: as it was observed that the Si4060 locks up occasionally
(after power up, as known..) caused by clock issues, and in case the
software contains error for flight - the watchdog was enabled with about
11 seconds reset interval. this is more than enough for all working
situations. tested and verified ok!

temp format fix: the temperature is now output as signed and correctly
converted to two character decimal. tested only for ~+30C - tests in
climate chamber should tell us more :)

adc: the get_battery_voltage function was finished by enabling the ADC.
it was tested with 0V, 3V and mid scale voltage - seems to fit nicely
doc fixes, error indication
util_test new tlm format