libfdisk: remove label specific get_freespace

 - it seems we can use improved nested<->container relationship
   rather than implement DOS specific function

Signed-off-by: Karel Zak <kzak@redhat.com>
cfdisk: improve tree output

Signed-off-by: Karel Zak <kzak@redhat.com>
libfdisk: (dos) fix ext_index usage

Signed-off-by: Karel Zak <kzak@redhat.com>
libfdisk: (dos) consolidate partition end-offset code

Signed-off-by: Karel Zak <kzak@redhat.com>
libfdisk: add dump functions, make freespace code generic

Signed-off-by: Karel Zak <kzak@redhat.com>
lib/tt: add tt_line_get_userdata()

Signed-off-by: Karel Zak <kzak@redhat.com>