man html index: Update index
- add link to cmap_keys(8)
- remove link to cpg_groups_get(3)
- add missing cpg_* and votequorum_qdevice_* functions
- corosync-fplay has already been removed by ab32894
Signed-off-by: Ferenc Wágner <wferi@niif.hu>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>