(sctstr): Member sct_che encoded number of che and their target.

(sctstr): Member sct_che encoded number of che and their target.
Simplify.  Split into member sct_che (number) and sct_che_target.
Users changed.
(get_che_cnum, set_che_cnum, get_che_value, get_che_value): Che
encoding/decoding functions; remove.
(CHE_MAX): Move from var.h to sect.h.
(prsect, doland): Print / edit the new field.