Rebuild executable with current tool chain, document build process

[mwittig]

See also https://forum.pimatic.org/topic/2460/installing-pimatic-0-9-osmc/ and osmc/osmc#339

I tried to build vhduino with the current tool chain with no joy. We also should setup a proper build script,e.g. cmake/make

g++ -Wall -DRF_CONTROL_VARDUINO=1 -c vhduino.cpp
g++ -Wall -DRF_CONTROL_VARDUINO=1 -c wiringx_rfcontrol.cpp
g++ -Wall -DRF_CONTROL_VARDUINO=1 -c wiringx_functions.cpp
g++ -Wall  vhduino.o wiringx_rfcontrol.o wiringx_functions.o ./wiringX/libwiringX.a -pthread -o vhduino
./wiringX/libwiringX.a(wiringX.c.o): In function `platform_register':
/home/pi/virtualhomeduino/wiringX/wiringX.c:103: undefined reference to `platforms'
/home/pi/virtualhomeduino/wiringX/wiringX.c:103: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o): In function `wiringXGC':
/home/pi/virtualhomeduino/wiringX/wiringX.c:129: undefined reference to `platforms'
/home/pi/virtualhomeduino/wiringX/wiringX.c:129: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o): In function `pinMode':
/home/pi/virtualhomeduino/wiringX/wiringX.c:140: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o): In function `digitalWrite':
/home/pi/virtualhomeduino/wiringX/wiringX.c:154: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o): In function `digitalRead':
/home/pi/virtualhomeduino/wiringX/wiringX.c:174: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o): In function `waitForInterrupt':
/home/pi/virtualhomeduino/wiringX/wiringX.c:192: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(wiringX.c.o):/home/pi/virtualhomeduino/wiringX/wiringX.c:210: more undefined references to `wiringXLog' follow
./wiringX/libwiringX.a(wiringX.c.o): In function `wiringXSetup':
/home/pi/virtualhomeduino/wiringX/wiringX.c:446: undefined reference to `platforms'
./wiringX/libwiringX.a(ci20.c.o): In function `ci20SPIDataRW':
/home/pi/virtualhomeduino/wiringX/ci20.c:480: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(ci20.c.o): In function `ci20SPISetup':
/home/pi/virtualhomeduino/wiringX/ci20.c:532: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(ci20.c.o): In function `ci20GC':
/home/pi/virtualhomeduino/wiringX/ci20.c:393: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(ci20.c.o): In function `ci20WaitForInterrupt':
/home/pi/virtualhomeduino/wiringX/ci20.c:362: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(ci20.c.o): In function `identify':
/home/pi/virtualhomeduino/wiringX/ci20.c:135: undefined reference to `wiringXLog'
./wiringX/libwiringX.a(ci20.c.o):/home/pi/virtualhomeduino/wiringX/ci20.c:449: more undefined references to `wiringXLog' follow
collect2: error: ld returned 1 exit status
Makefile:3: recipe for target 'all' failed