+20150912
+ + fixes for configure/build using clang on OSX (prompted by report by
+ William Gallafent).
+ + do not redefine "inline" in ncurses_cfg.h; this was originally to
+ solve a problem with gcc/g++, but is aggravated by clang's misuse
+ of symbols to pretend it is gcc.
+ + add braces to configure script to prevent unwanted add of
+ "-lstdc++" to the CXXLIBS symbol.
+ + improve/update test-program used for checking existence of stdc++
+ library.
+ + if $CXXLIBS is set, the linkage test uses that in addition to $LIBS
+