This annotation phases would have to be moved in optimization of normalized code

Changed the test-compile to use the horn-traces and the horn-queries option

Previously assert expression containing -> would lead to unnormalized ite. Now each expression within the assert is normalized and may bind new node equations.
This could be later optimized but is working now.

Revert the commit 384 by Xavier: adding dirname to the source_name introduced a bug: the .h file is empty!!! Strange behavior.

 useful for debugging and carrying correctness proofs to the C code level.
 non trivial result only when option -O 3 or above is activated.

- Header now do not allow the generation of function previously declared as C prototype

   local variables and global variables that are either cheap to evaluate
   or used no more than once.

 - changed the printing of unused variables

 - cleaner (but heavier !) code generation scheme for automata

 - one automata example added
 - changed the reset condition in node calls (now a simple bool expr)
 - bug corrected in clock calculus
 - bug corrected in traceability info
 - added field in variables to test whether they are original 
   or created by normalization process: better error message 
   for causality problems

 Warning: this is the first working version of automata, needs further 
 testing (and debugging). AFAIK, the semantics is close to Lustre V6,
 but further changes may be needed to equate them.