OFHTTPRequest: Add the current date if necessary.
OFStreamObserver_kqueue: Integer overflow check.

This is only relevant for platforms on which kqueue uses int for the
number of events instead of size_t.
Coding style.
Small conformance fix for OFHTTPServer + OFURL.
OFSet: Add a few new methods to create new sets.
Add of_tls_socket_class for 3rd-party TLS libs.

This removes of_http_client_tls_socket_class in favor of having one
symbol for all places where TLS would be desired.
Remove code that got useless.
Rename -[OFHTTPRequest postData] to POSTData.
Add -[description] for OFHTTPRequest(Result).
OFDataArray: Improve API.
OFHTTPServer: Fix handling of Host:.
Get rid of a wrongful GCC warning.
OFSet: Fix wrong argument type in interface.
OFHTTPRequest: Add property remoteAddress.
OFString: Improved API for getting C strings.
Add encodings for -[cStringUsingEncoding:].

This adds ISO 8859-1 and ASCII, ISO 8859-15 and Windows-1252 will
follow.
Add -[OFStream write{String,Line}:usingEncoding:].
OFStream: Fix a FIXME.
OFRunLoop: Use OFMutex instead of @synchronized.
Add -[stringByAppendingFormat:arguments:].