improve minilex use external parsing header

improve minilex use external parsing header

Clean up minilex
Move the header output to stdout
Introduce lexfile.h as the header output
Use lexfile.h in both minilex itself and lws
Add the following header support

       "Accept:",
       "If-Modified-Since:",
       "Accept-Encoding:",
       "Accept-Language:",
       "Pragma:",
       "Cache-Control:",
       "Authorization:",
       "Cookie:",
       "Content-Type:",
       "Date:",
       "Range:",
       "Referer:"

Signed-off-by: Andy Green <andy.green@linaro.org>