+20170218
+ + fix several formatting issues with manual pages.
+ + correct read of terminfo entry in which all strings are absent or
+ explicitly cancelled. Before this fix, the result was that all were
+ treated as only absent.
+ + modify infocmp to suppress mixture of absent/cancelled capabilities
+ that would only show as "NULL, NULL", unless the -q option is used,
+ e.g., to show "-, @" or "@, -".
+