Added new HTTP headers and WSI tokens:

 - "access-control-request-headers:" <-- WSI_TOKEN_HTTP_AC_REQUEST_HEADERS
 - "if-none-match:" <-- WSI_TOKEN_HTTP_IF_NONE_MATCH
Added comma after if-none-match...
Added HTTP_STATUS_NO_CONTENT == 204
Added optional per-header length limits:

 - libwebsockets.h:
 - * added struct lws_token_limits
   * added token limits pointer to lws_context_creation_info
 - private-libwebsockets.h: added token limits pointer to lws_context_creation_info
 - context.c: copy token limits in create_context
 - client.c / server.c: pass context when invoking libwebsocket_parse
 - parsers.c:
 - * libwebsocket_parse takes context pointer
   * issue_char takes context pointer and checks header length against context limits, if defined
   * issue_char returns 1 (not -1/0) for header too long, and spill: sets the state to WSI_TOKEN_SKIPPING
Added docs for token limits.
Reducing CPU cycles spent calculating per-header length limit.
Added HTTP OPTIONS support:

     - added options to minilex.c
     - regenerated lextable.h
     - added WSI_TOKEN_OPTIONS_URI to libwebsockets.h
     - tweaked parsers.c to accommodate OPTIONS token
     - tweaked server.c to set uri_ptr and uri_len for HTTP callback on OPTIONS as well
fix build on OpenBSD
dont free externally allocated user_space when closing connection

Signed-off-by: Andy Green <andy.green@linaro.org>
partial send handling
fix confusion ull in latency reporting
add runtime context flag to enforce defeat of OS CA CERTS even if build option selected

Signed-off-by: Andy Green <andy.green@linaro.org>
Trac 75: fix uxexpected ssl connection close
test server dumb increment fix once per second duplicate

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