Updated to tzdata2014g.
signal is C89, so assume it exists.
strerror is C89 , so assume it exists.
Include a constant in Stdio.Port for reuseport and fastopen support.

Especially SO_REUSEPORT needs different code if it is supported than when it is not.
perror test is not used.
Check that key in CertificatePair is set.
Allow add_cert private key to be a DER encoded string.
Improved non-crashing abilities.
expf, expl, floorf and floorl are C89, so assume they exists.
buffer isn't a member of the new ADT.struct
Don't crash on missing certificates.
Only generate keys when none are supplied. Call add_cert on the correct object.
Allow "read only once" more for input_from in IOBuffer.
The id in callbacks now defaults to the Stdio.File object

Note that this is never saved anywehere in this case,
it is just that if the id is 0 the object is used.

inputbuffering in blocking mode now mostly works.
The line_iterator now works (but is highly inefficient) in buffered mode.
Removed stdin/stderr/stdout variables in the 7.8 compat stdio.

Keeping them generates about 100 lines of warnings when the file is compiled due to
incompatible types for everything different between Fd_ref and Fd, more or less
Fixed autodoc syntax error
Check in the two new images created by 127f45
Fixed call_out test
Added get_certificates().