No longer using namespace boost,

doing that lead to conflicts in new compilers, because both boost and std contain a shared_ptr type.

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@1517 0fc631ac-6414-0410-93d0-97cfa31319b6

src/util/io/writer.cpp

@@ -13,6 +13,7 @@
 #include <util/version.hpp>
 #include <util/io/package.hpp>
 #include <boost/logic/tribool.hpp>
+using boost::tribool;
 
 // ----------------------------------------------------------------------------- : Writer