+20170624
+ + modify c++/etip.h.in to accommodate deprecation of throw() and
+ throws() in c++17 (prompted by patch by Romain Geissler).
+ + remove some incorrect calls for memory-leaks from 20170617 changes
+ (report by Allen Hewes).
+ + add test-programs for termattrs and term_attrs.
+ + modify _nc_outc_wrapper to use the standard output if the screen was
+ not initialized, rather than returning an error.
+ + improve checks for low-level terminfo functions when the terminal
+ has not been initialized (Redhat #1345963).
+ + modify make_hash to allow building with address-sanitizer,
+ assuming that --disable-leaks is configured.
+ + amend changes for number_format() in 20170506 to avoid undefined
+ behavior when shifting (patch by Emanuele Giaquinta).
+