An exception in that case most likely mean that the input is NaN.

Calling (= F F) or (> F ...) when F is NaN throws an arithmetic
exception in SBCL. Instead, we use the built-in predicate.

Fixes #302

Without IPv6 support.

Patch by Martin Simmons.

Add condition variable for non-threaded builds.

Protected by a read-time conditional denoting the feature.

We are using here builtin module "walker".

ECL is much safer than a few years ago. Especially thanks to giant
lock on compiler and other improvements. some problems were caused by
using unimplemented `condition-variable-timedwait' in `receive-if' –
we use now function which works fine, but doesn't support timeout. It
is the same as with MKCL and CLASP.

register-thread / find-registered

protected by feature condition ecl-weak-hash

Now it matches backend.lisp file – easier to navigate.

(This was possibly a workaround for helping Emacs indent this form properly.)

When encoding name in Emacs-style first line like ";; -- coding: utf-8; other: stuff --" is immediately followed by a semicolon, SLIME failed to parse the name correctly.

Note that this implementation does not capture values printed to
standard output. It is not clear that dynamically rebinding the
standard output port is possible in Kawa.

sb-kernel:%simple-fun-self is no more, but it's useless as it points
to itself.

Instead of checking for interrupts every N seconds notify the
condition variable that is used by RECEIVE-IF.

This requires an optional WAKE-THREAD implementation function, which
is added for SBCL, CCL and CLASP.

tempnam(NULL, NULL) uses "tmp." as a prefix, which made fasls compiled
from that file name all go into tmp.fasl.

more-count and more-context are used to get the actual &more value, no
need to show them.

@dkim points out that some contribs like slime-editing-commands and
slime-indentation are useful before (or without) connecting to a swank
server. Therefore, let's try and load them a bit earlier.

Partially reverts 9055a7e5.