had to add field fc_code_label to class FSignature
had to add field fc_code_label to class BlDenotationNode

Need to be careful of bit operations:
on bld_flags

X pass3/sigids
pass4/subst
pass4/findsig
pass5c/allocate
X pass5c/assessible
pass5c/bld_analyze
padd5d/sl_analyze
pass5d/traverse
X pass5d/codegen


In grammar tried change '\002' to INSERTIONCHAR

Decided to use Unicon modules to get effect of "file" statics in "c".
Will require some rework as I had been changing statics to globals - having
forgot about modules (or never understood). I never worked on anything this
large in Unicon and not much unicon in several years.
 
For some reason Modules did not work out - forget why.
