* Display the gxs id icons on nickname columns too & set a default header size for nickname*s column

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7539 b45a01b8-16f6-495d-af2f-9b41ad6348cc
changed back to use the default folder colored icons for channels treeWidget, it looks better

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7540 b45a01b8-16f6-495d-af2f-9b41ad6348cc