Fix extract_real (thanks Manuele), and add check for overflow.

cleaning up the code...

Fix remaining overflow checks.

remove incorrect include file.

Correctly implement MOD operation and overflow checks (still missing uint * / MOD).

Re-insert errno=0 before calling strtoXX() (thanks go to Manuele)

cosmetic changes.

Add data structure for storing overflow of constant values.

make the compiler platform independent (i.e. no longer assume sizeof(double)==8).

create extract_real_value() in absyntax_utils. NOTE: overflows not yet handled!

Update constant folding: fixing minor bug.

Fix a few bugs of previous commit.

Start constant_folding class.

little typo in last commited code
add if(is_bool_type(sym)) this->bool_type->accept(*this) in generate_c_il_c::visit(il_default_variable_c*)
to get .BOOLvar instead of .FALSEvar resp. .TRUEvar ..

Change return data type of array_dimension_iterator_c.next()

Fix SFC stage4 error.

Renamed class, remove unused code, delete allocated objects.

Start sematinc range check class.

Located variables may have other data types besides ANY_BIT.

Add verify_is_lvalue to control_variable in for_statement.

Remove useless code, and replace with assertion.

Fix bug: initialise un-initialised variable.

Delete incorrect comment.

Add some comments...