[libposix-development] Copyright notices completelly revised

[Henrique A. <hd...@gm...>]

 In the beginning of the project we were somewhat lazy with the
copyright notices, so I've fully revised them since the initial
commit. Now that the license is well defined, let's remember to always
insert a copyright notice when editing the files (this is specially
targeted at myself :-P).

-- 
 Henrique Dante de Almeida
 hd...@gm...