NTLM tests: boost coverage by forcing the hostname

A shared library tests/libtest/.libs/lihostname.so is preloaded in NTLM
test-cases to override the system implementation of gethostname().  It
makes it possible to test the NTLM authentication for exact match, and
this way test the implementation of MD4 and DES.

If LD_PRELOAD doesn't work, a debug build willl also workk as debug
builds are now made to prefer a specific environment variable and will
then return that content as host name instead of the actual one.

Kamil wrote the bulk of this, Daniel Stenberg polished it.

tests/data/test159

@@ -56,9 +56,18 @@ http
  <name>
 HTTP with NTLM authorization when talking HTTP/1.0
  </name>
+ <setenv>
+# we force our own host name, in order to make the test machine independent
+CURL_GETHOSTNAME=curlhost
+# we try to use the LD_PRELOAD hack, if not a debug build
+LD_PRELOAD=./libtest/.libs/libhostname.so
+ </setenv>
  <command>
 http://%HOSTIP:%HTTPPORT/159 -u testuser:testpass --ntlm -0
 </command>
+<precheck>
+chkhostname curlhost
+</precheck>
 </client>
 
 # Verify data after the test has been "shot"
@@ -66,11 +75,6 @@ http://%HOSTIP:%HTTPPORT/159 -u testuser:testpass --ntlm -0
 <strip>
 ^User-Agent:.*
 </strip>
-# We strip off a large chunk of the type-2 NTLM message since it depends on
-# the local host name and thus differs on different machines!
-<strippart>
-s/^(Authorization: NTLM TlRMTVNTUAADAAAAGAAYAEAAAAAYABgAWAAAAAAAAABwAAAACAAIAHAAAAA).*/$1/
-</strippart>
 <protocol>
 GET /159 HTTP/1.0
 Authorization: NTLM TlRMTVNTUAABAAAABoIIAAAAAAAAAAAAAAAAAAAAAAA=
@@ -79,7 +83,7 @@ Host: %HOSTIP:%HTTPPORT
 Accept: */*
 
 GET /159 HTTP/1.0
-Authorization: NTLM TlRMTVNTUAADAAAAGAAYAEAAAAAYABgAWAAAAAAAAABwAAAACAAIAHAAAAA
+Authorization: NTLM TlRMTVNTUAADAAAAGAAYAEAAAAAYABgAWAAAAAAAAABwAAAACAAIAHAAAAAIAAgAeAAAAAAAAAAAAAAABoKBAFpkQwKRCZFMhjj0tw47wEjKHRHlvzfxQamFcheMuv8v+xeqphEO5V41xRd7R9deOXRlc3R1c2VyY3VybGhvc3Q=
 User-Agent: curl/7.10.6-pre1 (i686-pc-linux-gnu) libcurl/7.10.6-pre1 OpenSSL/0.9.7a ipv6 zlib/1.1.3
 Host: %HOSTIP:%HTTPPORT
 Accept: */*