never executed code when -Wunreachable-code is used

targetos only and not build os. Commented away the line that enables perl
warnings.

with a wildcard DNS search domain.

more platforms.

build and link fine with c-ares

for SSPI support. The contents of the file has been moved into the krb4.h file.

works when built for win32.

exist.

work fine with cross-compiled builds.

the correct dynamic library names by default, and provides override switches
--with-ldap-lib, --with-lber-lib and --without-lber-lib.  Added
CURL_DISABLE_LDAP to platform-specific config files to disable LDAP
support on those platforms that probably don't have dynamic OpenLDAP
libraries available to avoid compile errors.

since there's no use building the whole test suite first and _then_ tell it
doesn't work anyway...