WyC: deprecated the use of "+" to signal list/string append.
WyC: deprecated the use of "+" to signal list/string append.

hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,Whiley/WhileyCompiler