General HTTP authentication cleanup and fixes

oops, a bad strtok() was fixed by Luca

Luca Altea's major HTTP Digest update

added include to fix warning

* Fixed a memory leak when doing repeated re-negotiations.
* Made the incoming line parser more forgiving to allow "name=contents" pairs
where the contents isn't within double quotes.
* M

* Fixed a memory leak when doing repeated re-negotiations.
* Made the incoming line parser more forgiving to allow "name=contents" pairs
where the contents isn't within double quotes.
* Made the digest code return CURLDIGEST_BADALGO if a requested algorithm
isn't supported by the code.

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first attempt to support stale=true

size_t/int fix

updated year in the copyright string

wrap at 80 cols

Access the user and passwd fields from the connectdata struct now instead
of the sessionhandle struct, as that was not good.

use CURLDEBUG instead of MALLOCDEBUG for preprocessor conditions

Better Digest stuff

hush the compiler

Initial Digest support. At least partly working.