When a node P::n1 wants to access to a node P::n2, it is ok to
search for it in the boby of P.

to avoid name clashes in the lic.

t, and a node returning such a t, the compiler was actually returning
the type definition of t (instead of the abstract type).

In  order  to fix  that,  it  was necessary  to  add  in argument  of
Lazycompiler.solve_x_idref  a  flag  (named provide_flag)  indicating
whether the  item being  compiled appears in  the provide, or  in the
body part of the package.

This fix  triggered another bug that  we also fix: indeed,  it is not
correct to return  a compile error when the  provided parameters of a
node is not equal to  its implementation. Indeed, such parameters can
be abstract type that are defined in that package.

The test "should_work/packEnvTest/packages.lus" is now ok.

	type 'a hereflagged =
	  Here of 'a
	| NotHere of Ident.long
into
	type 'a elt =
	  Local of 'a
	| Imported of Ident.long * static_arg list

i.e., i am basically doing two things:
 - fix poor naming
 - adding static arg to nodes

indeed, when compiling an equation that involves nodes defined
in another package, I need to check that the static args and the
static params match. Therefore I need to have the static params !
Therefore I add them (I will use them in the next commit).

Moreover, in SyntaxTreeCore.node_info, the static_params list was
an option type, which is a bit weird (empty lists are enough to
represent node with no static params).

tests.

Also, Add the possibility to have several lustre files in the
command-line arguments.

remove the power operator.

Define a lustre.lus that contains a packaged version of Lustre
predefined operators. It will be in the standard lustre library,
and should be accessible directly (path).

For non-regression tests, do not use Lazycompiler.test function
anymore and just use  LazyCompiler.node_check instead.

put in the new file compiledDataDump.ml all the stuff
related to string convertions of CompiledData items.

and anonymous structures. I've even found some type errors in the non-reg files!

To do that, we :

(1) totally remove  (in the  ocaml code) the  use of "oper",  and use
"node" instead.  Indeed, a node  is a memoryfull operator, as opposed
to function that are memoryless operators.  However, lus2lic does not
really care about memoryless  and memoryfull information. Therefore I
prefer  to use  node everywhere,  and to  flag node_info  to indicate
whether it has memories or not.

(2) change the syntaxTreeCore type to make it more general. Indeed,
    the distinction between functions and nodes was

    - redundant:  extern nodes  and (extern)  functions  were handled
    differently (NodeExtern versus ExtNode (was named FUNC before)).

    - and  incomplete:   it  was  not  possible   to  provide  static
      parameters to function, nor to define functions with body, etc.

Now a  function is  just a memoryless  node. The check  that function
indeed use no memory will be done later.

(3) also,  change  the  parser   so  that  functions  with  body  are
    accepted.

(4) in order  to do it step by  step, I add the  "extern" keyword" so
    that extern nodes and functions are more easy to parse. I will
    remove it later.

Better error msgs.

Renaming idents.

	 oper -> node
	 func -> extern node
	 node -> (user) node

	 CALL_BY_NAME -> STRUCT_n
	 STRUCT_EXP_n -> STRUCT_anonymous_n
	 flaged -> flagged

src/syntaxTreeCore.ml (new file)
	Split      syntaxTree.ml      into     syntaxTree.ml      and
	syntaxTreeCore.ml. The idea is that lic2loc should be able to
	use syntaxTreeCore.ml verbatim.

src/lxm.ml
src/lxm.mli
	remove pack_name from  this module, so that it  can be shared
	with  lic2loc too  (this is  mandatory  since it  is used  by
	SyntaxTreeCore)

src/compile.ml
src/compiledData.ml
src/evalConst.ml
src/evalConst.mli
src/evalType.ml
src/evalType.mli
src/expandPack.ml
src/lazyCompiler.ml
src/main.ml
src/parser.mly
src/symbolTab.ml
src/symbolTab.mli
src/syntaxTab.ml
src/syntaxTreeDump.ml
src/syntaxTreeDump.mli
src/test/Makefile
src/test/packs.lus
src/test/test.res.exp
	opening SyntaxTreeCore  module, and inline  the definition of
	Lxm.pack_name.

	Also,  begin  to  replace  oper  by node  or  predef_node  in
	identifiers, in order to get a more consistant naming scheme.

	Try to split this 400 lines (!) function.
	+ Factorize some duplicated code.

Ident.t is now an abstract data type (instead of a string).
fullid is turned into an Ident.long, and is also made abstract.

Add basic regression tests.

Add "assert false" statements everywhere it was necessary.

Add the fby operator in the syntax.