(*) os
Merge branch 'master' into os

Change in "master" is also relevant to "os"
(*) os
(+) OS led1 example
(^) led1: double link
(^) arduino ceu_go_* CEU_APP params
(^) os.pde => os.ino
(+) led1 complete
(+) os directory
(^) led1/ => gipo/
(+) serial.cpp (cpp => c)
(+) serial driver + test
(^) Makefile "target"
(+) app1
(^) ceu_sys_app/link
(^) invert start<=>link order
(+) ARDUINOSUB: Microduino
(^) ARDUINODIR=/opt/arduino
(+) app2
(^) simpler app
(+) app3
(^) app.ceu = tst.ceu+app.c
(^) app => tst
(+) shell
(+) shell tst2 serial
(+) shell serial fwd
(^) start/stop gpio
(^) minor adjustment