New authentication code added, particularly noticable when doing POST or PUT

with Digest or NTLM. libcurl will now use HEAD to negotiate the authentication
and when done perform the requested POST.

tests/data/test156

@@ -0,0 +1,79 @@
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 No Authorization Required swsclose swsbounce
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+Connection: close
+
+</data>
+
+<data1>
+HTTP/1.1 200 No Authorization Required swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+Connection: close
+
+PUT received fine. Thank you very much
+</data1>
+
+<datacheck>
+HTTP/1.1 200 No Authorization Required swsclose swsbounce
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+Connection: close
+
+HTTP/1.1 200 No Authorization Required swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+Connection: close
+
+PUT received fine. Thank you very much
+</datacheck>
+
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP PUT with --anyauth (when the server requires none)
+ </name>
+ <command>
+http://%HOSTIP:%HOSTPORT/156 -T log/put156 -u testuser:testpass --anyauth
+</command>
+<file name="log/put156">
+This is data we upload with PUT
+a second line
+line three
+four is the number of lines
+</file>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+HEAD /156 HTTP/1.1
+Host: 127.0.0.1:8999
+Pragma: no-cache
+Accept: */*
+
+PUT /156 HTTP/1.1
+User-Agent: curl/7.10.5 (i686-pc-linux-gnu) libcurl/7.10.5 OpenSSL/0.9.7a ipv6 zlib/1.1.3
+Host: 127.0.0.1:8999
+Pragma: no-cache
+Accept: */*
+Content-Length: 85
+Expect: 100-continue
+
+This is data we upload with PUT
+a second line
+line three
+four is the number of lines
+</protocol>
+</verify>