Check response code, make sure it's 101.
Pass http_message to the client to keep it appraised.
This represents a slight change in the API -
in case of an error MG_EV_WEBSOCKET_HANDSHAKE_DONE will now be delivered where previosuly connection would just hang.
Clients that do not examine the argument may for a moment think handshake has succeeded but in fact connection will be closed immediately.
CL: mg: Fix handling of WS handshake error response
PUBLISHED_FROM=645a43d9e5bee216e54411f85827c9b974e9a7d1
cs_log_set_filter() is removed in favor of cs_log_set_file_level() which
allows setting log verbosity of individual files and/or lines.
E.g.: `mg_=1,mjs=1,=4` - level for for everything except mjs and mongoose.
We use the fact that we are usually pretty careful with our file names and use prefixes consistently.
In mos, `debug.file_level` sets the option on boot and `Sys.SetDebug` is updated to parse `file_level` option to change it at runtime.
CL: Log file:line instead of function; add cs_log_set_file_level()
PUBLISHED_FROM=49f18d4d0d3dd224865129a4f8fe6cccd1d9bc12
Which is a replacement of (deprecated) `mg_http_parse_header`, but,
similarly to `asprintf`, allocates a new buffer if the client-provided
one is not large enough.
Also use it throughout mongoose code, and thus some header-related
limitations are removed; in particular,
https://github.com/cesanta/mongoose/issues/813 is fixed.
CL: Mongoose Web Server: Deprecate `mg_http_parse_header()` and implement `mg_http_parse_header2()` instead, which allocates a new buffer if the client-provided one is not large enough (similarly to `asprintf`).
CL: Mongoose Web Server: Fix limitations of header value lengths, e.g. when parsing authentication headers such as nonce, etc.
PUBLISHED_FROM=c75b1bbbbdb294ea85075ce69b1368f115fdd1ef
