gitignore files generated by native code compilation

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/acg/dev/trunk@607 8fde8617-4931-0410-9586-bc38d6d3f018
Show: Aligning the lines of sister nodes

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/acg/dev/trunk@608 8fde8617-4931-0410-9586-bc38d6d3f018
Show: fix centering of trees

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/acg/dev/trunk@609 8fde8617-4931-0410-9586-bc38d6d3f018