UI cleanup: fixed texture is a 2d image painting option, hide in 3D viewport toolbar

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53478 954f8c5b-7b00-dc11-b283-0030488c597c
remove vertex selection check for weight paint mode so you can paint `through` the mesh.

also made the wire draw without depth masking when the depth check is off, similar to mesh editmode drawing, nice hint about whats going on.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53479 954f8c5b-7b00-dc11-b283-0030488c597c