URI handling of IPv6 addresses could be improved

[JeffDavie]

Here is a patch that we are using to improve IPv6 handling by the uri.hpp code. Currently, the class does not return valid URI strings when an IPv6 address is used. If the changes are acceptable, consider rolling into 0.8.0.

patch.ws_uri_ipv6_support.txt

[mstaz]

The server side of WebSocket++ validates the Host field of incoming HTTP requests and requires IPv6 addresses to be enclosed with squared brackets (how it is defined in RFC3986). Unfortunately the client side removes this squared brackets and with that doesn't work reliably with the server side.
To be more precise in that case the server side treats IPv6 addresses (with standard port) as hostnames and tries to parse the last part of the address as port number. If a character (a-f) is contained, the validation fails and connection is rejected.
So maybe would it be a simpler and quicker solution to just not remove the squared brackets from IPv6 addresses when complete URI is passed as string?

[barsnick]

I have encountered the identical issue with numerical IPv6 addresses (and an explicit port). I can confirm that the attached patch or rather PR #879 solved it for me.

[zaphoyd]

An update has been pushed to the develop branch that overhauls URI validation (especially for the authority component). WebSocket++ is now able to distinguish between many types of valid and invalid hostnames and literal IP addresses based on the rules in RFC3986. When valid IPv6 literal addresses are used (including when they are passed directly to the constructor hosts without brackets), URI strings generated will be RFC3986 compliant with the proper square brackets.

Thank you everyone here for your patience, patch examples, and testing.