Adopt STL naming convention in ErrnoHelper.hh
Adopt STL naming convention in ErrorLevel.hh
Remove FUNCTIONAL_INITIALIZE

It doesn't look very useful...
Adopt STL naming convention in FunctionalInitialize.hh
Remove unused IDENTITY
Rename Identity to identity
Adopt STL naming convention in IntegerSequence.hh
Rename Nop to nop
Adopt STL naming convention in TypeTag.hh