- tests/ret.cc: Update.
- mlc/ret.hh: Fix missing include.

The Boolean value classes are re-written and internal::value_ is
removed; this class was too ambiguous since precise types, e.g.,
int_<i>, are provided and it was weirdly located in the value class
hierarchy.

- mlc/bool.hh (bool_<true>, bool_<false>): Merge those
specializations into the single and once for all written class
bool_<b>.
(bool_<true>::is_true): Remove since this mark is now factored
in the base class bexpr_is_<b>.
(bool_<b>): Add inheritance so that a Boolean value can be
considered as a Boolean expression type.
(internal::value_<bool, b>): Remove this specialization since
the class internal::value_ is also removed.
(logic.hh): Remove inclusion.
(mlc_bool): Move to...

The Boolean expression types are now handled by special classes.
Yet mlc::true_ and mlc::false_ remain expression types in addition
of value types.

- mlc/bexpr.hh: ...this file.  This macro only applies on Boolean
expression types.
(bexpr_): Remove this obsolete wrapper.
(bexpr_is_<b>): New base class with its couple of specializations
which act as a replacement for bool_<b> for expression types.
(internal::bool_of_): Replace the meta-code for mlc_bool.

Those changes induce a lot of updates described below.

- mlc/pair.hh: Update includes.
- mlc/logic.hh: Update.  Instead of deriving from bool_<b>
Boolean expression types now derive from bexpr_is_<b>.
(and_list_, or_list_): Comment to postpone updating while keeping
code compile.
- mlc/implies.hh: Update inheritance.
- mlc/if.hh: Update includes and add assertion.
- mlc/assert.hh: Update includes.
- mlc/valist.hh: Likewise.
- mlc/wrap.hh: Remove obsolete code.
- mlc/is_a.hh: Update inheritance.
(bexpr_): Replace by wrap_.
- mlc/case.hh: Update.  Now use mlc_bool instead of ::value.
- mlc/cmp.hh: Update inheritance.
(eq_::ensure): Remove this obsolete feature.
- mlc/value.hh: Move sub-classes of value to...
- mlc/int.hh, mlc/char.hh: ...these new files.
- mlc/values.hh: New file that includes the whole value types material.


git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@429 4aad255d-cdde-0310-9447-f3009e2ae8c0