Very minor tweak to the emacs mode to include "assume" statements.
Very minor tweak to the emacs mode to include "assume" statements.

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