TODO: remove "Happy Eyeball dual stack connect"

 1.3 struct lifreq

 1.4 signal-based resolver timeouts

 1.5 get rid of PATH_MAX

 1.6 Happy Eyeball dual stack connect

 1.7 Modified buffer size approach

 1.6 Modified buffer size approach

 2. libcurl - multi interface

 2.1 More non-blocking

 we need libssh2 to properly tell us when we pass in a too small buffer and

 its current API (as of libssh2 1.2.7) doesn't.

1.6 Happy Eyeball dual stack connect

 In order to make alternative technologies not suffer when transitioning, like

 when introducing IPv6 as an alternative to IPv4 and there are more than one

 option existing simultaneously there are reasons to reconsider internal

 choices.

 To make libcurl do blazing fast IPv6 in a dual-stack configuration, this needs

 to be addressed:

    http://tools.ietf.org/html/rfc6555

1.7 Modified buffer size approach

1.6 Modified buffer size approach

 Current libcurl allocates a fixed 16K size buffer for download and an

 additional 16K for upload. They are always unconditionally part of the easy