Added

acc,
acc/value (observable),
button,
button/value (observable)

The oBIX contract for acc needs to be set to a correct contract.

Be careful with resource titles: if the sum of all title lengths
is greater than a specific limit, the error BlockOutScope might
occur.

new file:   iotsys/Makefile
new file:   iotsys/README.md
new file:   iotsys/iotsys-gc-receiver.c
new file:   iotsys/iotsys-gc-sender.c
new file:   iotsys/iotsys-gc.csc
new file:   iotsys/iotsys-group-communication.c
new file:   iotsys/iotsys-server.c
new file:   iotsys/iotsys.csc
new file:   iotsys/project-conf.h