v0.4.4
  - Better error reporting on typing declarations
  - type aliases
v0.4.3
  New features:
  - when infering the type of predicates and constraints, TCLP now uses
    type information provided by the programmer in order to treat smaller
    parts of the source code at once (that is it uses type information to
    break connex components of the call graph into smaller pieces).
  - if no m.typ file is found when encountering use_module(m), TCLP now 
    tries to type check m.pl
  Minor changes:
  - updated syntax error message, so it is compatible with emacs
  - the .typ file for modules that are currently type checked is now optional
v0.4.2
  New features:
  - a cache system for the type structure has been implemented. This a speed
    up for computing the type order.
  Bugfixes:
  - prints errors of typeof declarations
  - prints names correctly when encountering an error with 
    --option nodefault
v0.4.1
  New features:
  - DCG expansion (thanks to D. De Rauglaudre).
  - prints the type of variables when finding an error in a clause.
  - possibility to disable the default type term x term x ... x term -> term
    for function symbols (using command line arguments --option nodefault).
v0.4
  Bugfixes
  - bugfix for MacOSX: added missing libraries in the link phase.
  - in type check, when doing type inference, a bug appeared when then head of
    the clause has the wrong type (for example, when a chr constraint
    was declared of type pred instead of chr_constraint) instead of
    correctly reporting the error.

  Speed improvements
  - uses backtracking to reinitialize solvers in between type checking of two 
    connex parts.
  - added some checks to avoid propagating type constraints that dont change 
    anything.
  - removed intermediate type variables in type checking.
  - type constraints (X :< Y , Y :< X) are simplified into X = Y.

  Minor updates
  - added an error when declaring a type constructor twice but with a 
    different number of arguments.
  - clauses for the predicate tclp__files:file_search_path/2 can be added so 
    tclp can find module of the form some(thing) (same use as
    user:file_search_path/2).
  - error messages should be in one line now
  - added keyword `subtype' as an alias for `order'

  Type libraries updates
  - added code to handle grammar in GNU-Prolog type libraries
  - some bugfixes

  Command line options
  - Removed some (not very useful) switches
v0.3b
  - bugfix in type inference when heuristics fail
v0.3
  - created a tclp subdir in the src directory
  - now tclp executable uses the tclp library
  - auto location of the tclp directory: one doesn't need to specify were are
    the standard type libraries
  - the strong typing of equality is now available only via an option
    (--strong_eq), since it does not corresponds to the true type discipline
     of tclp
  - fixed a bug in type inference (was too restrictive and didn'nt
    provided the term x ... x term -> pred type by default)
  - added the manual

v0.2.99h (was an experimental version)
  - changed the typing of equality: now =/2 is typed in a way such that both 
    of its arguments must have the same type. Before, they were asked to 
    have a common supertype. This provides a stricter type checking and a 
    more precise type inference.

v0.2.99g
  - fixed bug in the type constraint solver that could have make it loop.
  - added library of types for GNU Prolog
  - now provides a way to install tclp as a library for sicstus.
  - the handling of ',' and 'op' has been moved to the corelib.typ files

v0.2.99f
  - added the possibility to change the type of predicates defined by a clause:
    ex: +: defines a 'fd_constraint' and not a 'pred'.
    - changed type libraries to use this
    - added tclp__define_clause_op(Operator,TypeOfPredicate)
    - Heads in tclp__define_clause(Clause,Location,Heads,Bodies(,Conditions)) 
      are now triplets (Head - HeadLocation - HeadType)
  - removed computing of connex parts when doing type check only
  - added connex component timing when -v actions -v timing are enabled
  - implemented a heuristic for choosing the next overloaded symbol to 
    disambiguate
