Update Version 1.12:
  - Bugfix (major): long function names caused wrong annotations. (lp_solve ignores constraints having to long lables)
  - Underscores are allowed within matches now. Nested scopes of "underscore"-identifiers do not cause any problem.
  - Code-shuffle: "Context.add" replaced by "bind"       throughout constraint.ml
  - Code-shuffle: "Stack.add"   replaced by "stack_bind" throughout exec.ml
  - Warnings are delayed now during execution without option -debug
  - Manual LFD_MANUAL.tex updated (...)
