interface_to_sa no longer server only

Via "DevYourWorld" on github

https://github.com/warmcat/libwebsockets/issues/64

Signed-off-by: Andy Green <andy.green@linaro.org>
update cmake opts in README.build

via "DevYourWorld" on github

https://github.com/warmcat/libwebsockets/issues/64

Signed-off-by: Andy Green <andy.green@linaro.org>
fix WITHOUT_CLIENT install in CMake

Via "DevYourWorld" on github

https://github.com/warmcat/libwebsockets/issues/64#issuecomment-35719084

Signed-off-by: Andy Green <andy.green@linaro.org>
fix visibility of return_http_status

From "DevYourWorld" on github

https://github.com/warmcat/libwebsockets/issues/64#issuecomment-35720037

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