Add libwebsockets as thirdparty library.

License is LGPLv2.1 + static linking exception, version is 2.4.1

thirdparty/lws/lextable-strings.h

@@ -0,0 +1,104 @@
+/* set of parsable strings -- ALL LOWER CASE */
+
+#if !defined(STORE_IN_ROM)
+#define STORE_IN_ROM
+#endif
+
+STORE_IN_ROM static const char * const set[] = {
+	"get ",
+	"post ",
+	"options ",
+	"host:",
+	"connection:",
+	"upgrade:",
+	"origin:",
+	"sec-websocket-draft:",
+	"\x0d\x0a",
+
+	"sec-websocket-extensions:",
+	"sec-websocket-key1:",
+	"sec-websocket-key2:",
+	"sec-websocket-protocol:",
+
+	"sec-websocket-accept:",
+	"sec-websocket-nonce:",
+	"http/1.1 ",
+	"http2-settings:",
+
+	"accept:",
+	"access-control-request-headers:",
+	"if-modified-since:",
+	"if-none-match:",
+	"accept-encoding:",
+	"accept-language:",
+	"pragma:",
+	"cache-control:",
+	"authorization:",
+	"cookie:",
+	"content-length:",
+	"content-type:",
+	"date:",
+	"range:",
+	"referer:",
+	"sec-websocket-key:",
+	"sec-websocket-version:",
+	"sec-websocket-origin:",
+
+	":authority",
+	":method",
+	":path",
+	":scheme",
+	":status",
+
+	"accept-charset:",
+	"accept-ranges:",
+	"access-control-allow-origin:",
+	"age:",
+	"allow:",
+	"content-disposition:",
+	"content-encoding:",
+	"content-language:",
+	"content-location:",
+	"content-range:",
+	"etag:",
+	"expect:",
+	"expires:",
+	"from:",
+	"if-match:",
+	"if-range:",
+	"if-unmodified-since:",
+	"last-modified:",
+	"link:",
+	"location:",
+	"max-forwards:",
+	"proxy-authenticate:",
+	"proxy-authorization:",
+	"refresh:",
+	"retry-after:",
+	"server:",
+	"set-cookie:",
+	"strict-transport-security:",
+	"transfer-encoding:",
+	"user-agent:",
+	"vary:",
+	"via:",
+	"www-authenticate:",
+
+	"patch",
+	"put",
+	"delete",
+
+	"uri-args", /* fake header used for uri-only storage */
+
+	"proxy ",
+	"x-real-ip:",
+	"http/1.0 ",
+
+	"x-forwarded-for",
+	"connect ",
+	"head ",
+	"te:",		/* http/2 wants it to reject it */
+
+	"", /* not matchable */
+
+};