(PRI_SMAINT, PRI_PMAINT, PRI_LMAINT, PRI_SBUILD, PRI_PBUILD,

(PRI_SMAINT, PRI_PMAINT, PRI_LMAINT, PRI_SBUILD, PRI_PBUILD,
PRI_LBUILD): Turn macros into enumeration constants.  Value
SCT_MAXDEF+1 was previously unused; use it.
(PRI_MAX): New; replacing the horrible SCT_MAXDEF+8.

(show_sect_build): Simply examine all sector types, don't skip the
first five.  The code ignores them just fine.

(show_sect_build, show_sect_stats, show_sect_capab): Don't try to show
sector types beyond SCT_MAXDEF.  The table has some empty extra slots,
for whatever reasons; no use examining them.