GCC_ATTR_UNUSED -> OCTAVE_UNUSED in packages (here: odepkg)

[Schöps , Sebastian]

Dear all, 

as far as I can see "GCC_ATTR_UNUSED" was recently renamed to "OCTAVE_UNUSED". 
This breaks compatibility with some packages (e.g. odepkg). In the case of 
odepkg the fix is rather easy (just a search and replace exercise) since the 
next release of odepkg will be for >=4.1 only anyway. However, other packages 
may want to stay backward compatible and may need "if defined" statements.

@Jack: maybe I forgot, but is there already a repository with the new 
development branch for >=4.1? I could commit the (simple) changeset.

Bye
Sebastian