packed lengths and numbers seem to work in C and Java

compiler/C_CodeGen.jrag

compiler/Signature.jrag

examples/simple/example_decoder.c

lib/c/experimental/pack.c

lib/c/labcomm.c

lib/c/labcomm_private.h

lib/java/se/lth/control/labcomm/LabCommDecoder.java

lib/java/se/lth/control/labcomm/LabCommDecoderChannel.java

lib/java/se/lth/control/labcomm/LabCommEncoder.java

lib/java/se/lth/control/labcomm/LabCommEncoderChannel.java