cairo package renaming, lablgl support for lablgtk2

[william3]

Hello,
two commits :

• cairo : package rename. it is important, because opam use the directory name to install ocamlfind META package. Without change, cairo1.ocaml opam package installs "cairo" ocamlfind package in cairo sub directory, which could be fine, but "cairo.0.4.x" opam package get installed in same cairo sub directory...
  to solve this, the best is to name opam package the same as ocamlfind package, that is to say :
  cairo1.ocaml-1.2.0 -> cairo.1.2.0 with cairo ocamlfind package (ocamlfind package not changed, only opam name);
  cairo.0.4.4 -> cairo2.0.4.4 with cairo2 ocamlfind package (ocamlfind package not changed, only opam name)
• lablgtk2 :
  due to ocamlfind default install directory being in lib and not in lib/ocaml, (and lablGL -> lablgl renaming), it generates a problem with lablgl support in lablgtk2. solved with this commit

[samoht]

Can you please confirm on https://github.com/OCamlPro/opam-repository/issues/955 that your fine to license these patches to CC0 ?

[william3]

I am not in the list, which is normal, as it is my first commit...

[samoht]

We are in the process of migrating the repository to CC0, so I'm trying to keep track of new contributors as well (it will be easier later when the LICENSE file will clearly located at the root of the repository). But until then, I still need to ask you to confirm that you are happy with CC0 somewhere (and the existing thread seems a good place to do so, I'll add your name on the list at the same time).

[samoht]

Thanks!