In  short, the  rationale for  this change,  is that  it is  having a
recursive node_exp is
- useless,
- too complicated,
- wrong w.r.t. nesting iterator calls

In long:

- It is useless because, at the  Eff level, a node cannot call itself
  via one  of its  static arg (which  was where the  recursivity came
  from).

- and indeed, it  is much simpler to consider that  a static arg node
  can only be ident.long that identifies a node alias.

  This  means of  course, that  nested iterators  have  been unnested
  before,   inventing  alias   node  names   along  the   way...  And
  polymorphism makes thing difficult once again.

- But the  *big* problem  with a recursive  node_exp is that  it make
  things very  complicated to (lic)dump nested  iterator call because
  of polymorphism!   Actually, it  even makes thing  complicated when
  the iterators were themselves not nested in the source code !

  Some ugly  things were done in  LicDump to unnest  those calls when
  printing node_exp.   But this uglyness  have a price:  tricky code,
  and bugs! Indeed, nested iterators calls were wong for example when
  using  the --inline-iterator  mode (but  i would  not  be surprised
  that is wrong in other cases...).

Hence,  LicDump  is  simpler,  but  of course  LazyCompiler  is  more
complicated.  But  this  is  reasonable:  a  pretty-printer  is  not
supposed to be complicated.

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).

not compile them is (well, was) the default...).

also, during pretty-printing, remove the type in the constant definition
(e.g., "const x = 42;" instead of "const x = 42:int;"), except if it is an abstract
constant of course

values could not be exported, while expandPack.ml was exporting it.

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.