* Rename BControlLook::ComposeItemSpacing() to ComposeSpacing(), and extend it to handle the new constants.
* Adjust users of BControlLook::ComposeItemSpacing() accordingly.
* part of #7447
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42025 a95241bf-73f2-0310-859d-f6bbb57e9c96