Release OpenSceneGraph-3.4.1-rc2

Release OpenSceneGraph-3.4.1-rc1

Release OpenSceneGraph-3.5.6

Release OpenSceneGraph-3.5.5

Release OpenSceneGraph-3.5.4

Release OpenSceneGraph-3.5.3

Release OpenSceneGraph-3.5.2

OpenSceneGraph-3.4.0 stable release

Updated ChangeLog for 3.5.1 dev release

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15181 16af8721-9629-0410-8352-f15c8da7e697

From Kristofer Tingdahl, "we had a minor shadow problem with the osg-…

…3.4 that pollutes our continuous integration"

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15143 16af8721-9629-0410-8352-f15c8da7e697