(pchrstr, pchr_ca, pchr, sctstr, dchr_ca, dchr): Replace pchrstr

member p_effic by sctstr member d_peffic.  Tables updated.
(show_sect_capab): Adapted.
(prod_eff): Adapted; requires changing first parameter to sector type.
Callers changed.
(P_MDUST): Remove, because pchr[P_MDUST] now identical to
pchr[P_DUST].

include/sect.h

@@ -99,6 +99,7 @@ struct dchrstr {
     unsigned char d_uid;
     char d_mnem;		/* map symbol */
     int d_prd;			/* product type */
+    int d_peffic;		/* process efficiency, in percent */
     int d_mcst;			/* movement cost */
     d_navigation d_nav;		/* navigation capability */
     i_packing d_pkg;		/* type of packaging in these sects */