Adopt STL naming convention in Variant.hh
Adopt STL naming convention in VariantTest.cc
Adopt STL naming convention in Maybe.hh
Rename MaybeTest.cc to maybe_test.cc
Adopt STL naming convention in maybe_test.cc
Adopt STL naming convention in Message.hh
Rename OutputStream to xostream

Like xchar and xstring.
Adopt STL naming convention in Reference.hh
Adopt STL naming convention in SharedFunction.hh
Rename StaticCast to static_cast_function
Rename OutputStringStream to xostringstream
Adopt STL naming convention in Trie.hh