cli: Fix invalid option message.

ascii code was being printed.
gui: Fix debug build.
apitrace README.markdown correct some typos

Reading through some of the documentation, spotted some typos
and thought might as well correct them while reading

Mostly missing or incomplete words. One section that meant to
display code didn't have the correct format to display it as such.

Signed-off-by: Lawrence L Love <lawrencex.l.love@intel.com>
readme: Provide a GLEW_KHR_debug example instead of GLEW_GREMEDY_string_marker.