i108228 - table: bool has negative sign when used in formula expression.

The root problem is that the boolean expression "true"
evaluates to -1 rather than +1 in formulas in Writer.

The problem is solved by considering that the type can
be a Boolean (SBxBool in addition to SbxSTRING.

Author:	Mattias Johnnson

sw/source/core/bastyp/calc.cxx

@@ -1760,7 +1760,7 @@ double SwSbxValue::GetDouble() const
 
 SwSbxValue& SwSbxValue::MakeDouble()
 {
-    if( SbxSTRING == GetType() )
+    if( SbxSTRING == GetType() || SbxBOOL == GetType() )
         PutDouble( GetDouble() );
     return *this;
 }